First time I've seen this (Ian suggests it is probably a clash with Modbot) but I guess I should report it anyway.

Error:

Caught exception in MusicBrainz::Server::Controller::Edit->enter_votes "DBD::Pg::st execute failed: ERROR: deadlock detected
DETAIL: Process 18490 waits for ShareLock on transaction 522488671; blocked by process 17409.
Process 17409 waits for ShareRowExclusiveLock on relation 1862129 of database 1416385; blocked by process 18490.
HINT: See server log for query details.
CONTEXT: SQL statement "SELECT 1 FROM ONLY "musicbrainz"."edit" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF x" at lib/Sql.pm line 414.
at lib/Sql.pm line 429
Sql::_ANON_('DBD::Pg::st execute failed: ERROR: deadlock detected\x

{a}

DETAIL:...') called at local/lib/perl5/Try/Tiny.pm line 100
Try::Tiny::try('CODE(0xf4f28d8)', 'Try::Tiny::Catch=REF(0xc294828)') called at lib/Sql.pm line 430
Sql::_select_list('Sql=HASH(0xcf17040)', 'INSERT INTO vote (editor, edit, vote) VALUES (?, ?, ?) RETURN...', 'ARRAY(0xf5469a8)', 'hashref') called at lib/Sql.pm line 458
Sql::select_list_of_hashes('Sql=HASH(0xcf17040)', 'INSERT INTO vote (editor, edit, vote) VALUES (?, ?, ?) RETURN...', 326637, 18818457, -1) called at lib/MusicBrainz/Server/Data/Vote.pm line 111
MusicBrainz::Server::Data::Vote::_ANON_() called at lib/Sql.pm line 281
Sql::_ANON_() called at local/lib/perl5/Try/Tiny.pm line 76
eval

{...} called at local/lib/perl5/Try/Tiny.pm line 67
Try::Tiny::try('CODE(0xcf224f0)', 'Try::Tiny::Catch=REF(0xcf17da8)') called at lib/Sql.pm line 294
Sql::_auto_transaction('CODE(0xcf215d8)', 'Sql=HASH(0xcf17040)') called at lib/Sql.pm line 299
Sql::_run_in_transaction_one('CODE(0xcf215d8)', 'Sql=HASH(0xcf17040)') called at lib/Sql.pm line 313
Sql::run_in_transaction('CODE(0xcf215d8)', 'Sql=HASH(0xcf17040)') called at lib/MusicBrainz/Server/Data/Vote.pm line 139
MusicBrainz::Server::Data::Vote::enter_votes('MusicBrainz::Server::Data::Vote=HASH(0xb3cb920)', 326637, 'HASH(0xce1f0d8)', 'HASH(0xce21ab0)') called at lib/MusicBrainz/Server/Data/Edit.pm line 625
MusicBrainz::Server::Data::Edit::_ANON_() called at lib/Sql.pm line 281
Sql::_ANON_() called at local/lib/perl5/Try/Tiny.pm line 76
eval {...}

called at local/lib/perl5/Try/Tiny.pm line 67
Try::Tiny::try('CODE(0xcf17a90)', 'Try::Tiny::Catch=REF(0xce78b88)') called at lib/Sql.pm line 294
Sql::_auto_transaction('CODE(0xce2a128)', 'Sql=HASH(0xcf17040)') called at lib/Sql.pm line 299
Sql::_run_in_transaction_one('CODE(0xce2a128)', 'Sql=HASH(0xcf17040)') called at lib/Sql.pm line 313
Sql::run_in_transaction('CODE(0xce2a128)', 'Sql=HASH(0xcf17040)') called at lib/MusicBrainz/Server/Data/Edit.pm line 634
MusicBrainz::Server::Data::Edit::insert_votes_and_notes('MusicBrainz::Server::Data::Edit=HASH(0xa9881a0)', 326637, 'votes', 'ARRAY(0xce2a260)', 'notes', 'ARRAY(0xce2a920)') called at lib/MusicBrainz/Server/Controller/Edit.pm line 77
MusicBrainz::Server::Controller::Edit::enter_votes('MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0xbdc64c0)', 'MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst.pm line 1667
eval

{...} called at local/lib/perl5/Catalyst.pm line 1667
Catalyst::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc64c0)') called at local/lib/perl5/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc64c0)') called at lib/MusicBrainz/Server.pm line 322
MusicBrainz::Server::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc64c0)') called at local/lib/perl5/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0xbdc64c0)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Controller.pm line 125
Catalyst::Controller::_ACTION('MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0xbdc19c0)', 'MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst.pm line 1667
eval {...}

called at local/lib/perl5/Catalyst.pm line 1667
Catalyst::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc19c0)') called at local/lib/perl5/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc19c0)') called at lib/MusicBrainz/Server.pm line 322
MusicBrainz::Server::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc19c0)') called at local/lib/perl5/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0xbdc19c0)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Dispatcher.pm line 257
Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x329a900)', 'forward', 'MusicBrainz::Server=HASH(0xc0cce10)', '_ACTION') called at local/lib/perl5/Catalyst/Dispatcher.pm line 237
Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x329a900)', 'MusicBrainz::Server=HASH(0xc0cce10)', '_ACTION') called at local/lib/perl5/Catalyst.pm line 342
Catalyst::forward('MusicBrainz::Server=HASH(0xc0cce10)', '_ACTION') called at local/lib/perl5/Catalyst/Controller.pm line 99
Catalyst::Controller::_DISPATCH('MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Action.pm line 65
Catalyst::Action::execute('Catalyst::Action=HASH(0xbdc15a0)', 'MusicBrainz::Server::Controller::Edit=HASH(0xba90d88)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst.pm line 1667
eval

{...} called at local/lib/perl5/Catalyst.pm line 1667
Catalyst::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc15a0)') called at local/lib/perl5/Catalyst/Plugin/StackTrace.pm line 94
Catalyst::Plugin::StackTrace::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc15a0)') called at lib/MusicBrainz/Server.pm line 322
MusicBrainz::Server::execute('MusicBrainz::Server=HASH(0xc0cce10)', 'MusicBrainz::Server::Controller::Edit', 'Catalyst::Action=HASH(0xbdc15a0)') called at local/lib/perl5/Catalyst/Action.pm line 60
Catalyst::Action::dispatch('Catalyst::Action=HASH(0xbdc15a0)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst/Dispatcher.pm line 257
Catalyst::Dispatcher::_do_forward('Catalyst::Dispatcher=HASH(0x329a900)', 'forward', 'MusicBrainz::Server=HASH(0xc0cce10)', '/edit/_DISPATCH') called at local/lib/perl5/Catalyst/Dispatcher.pm line 237
Catalyst::Dispatcher::forward('Catalyst::Dispatcher=HASH(0x329a900)', 'MusicBrainz::Server=HASH(0xc0cce10)', '/edit/_DISPATCH') called at local/lib/perl5/Catalyst.pm line 342
Catalyst::forward('MusicBrainz::Server=HASH(0xc0cce10)', '/edit/_DISPATCH') called at local/lib/perl5/Catalyst/Dispatcher.pm line 105
Catalyst::Dispatcher::dispatch('Catalyst::Dispatcher=HASH(0x329a900)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst.pm line 1613
Catalyst::dispatch('MusicBrainz::Server=HASH(0xc0cce10)') called at lib/MusicBrainz/Server.pm line 286
Class::MOP::Class:::around('CODE(0x2ba0a28)', 'MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/x86_64-linux-gnu-thread-multi/Class/MOP/Method/Wrapped.pm line 162
Class::MOP::Method::Wrapped::_ANON_('MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/x86_64-linux-gnu-thread-multi/Class/MOP/Method/Wrapped.pm line 91
MusicBrainz::Server::dispatch('MusicBrainz::Server=HASH(0xc0cce10)') called at local/lib/perl5/Catalyst.pm line 1963
Catalyst::_ANON_() called at local/lib/perl5/Try/Tiny.pm line 76
eval {...}

called at local/lib/perl5/Try/Tiny.pm line 67
Try::Tiny::try('CODE(0xc044480)', 'Try::Tiny::Catch=REF(0xc0ebb38)') called at local/lib/perl5/Catalyst.pm line 1969
Catalyst::handle_request('MusicBrainz::Server', 'env', 'HASH(0xc044540)') called at local/lib/perl5/Catalyst/Plugin/AutoRestart.pm line 117
Catalyst::Plugin::AutoRestart::handle_request('MusicBrainz::Server', 'env', 'HASH(0xc044540)') called at local/lib/perl5/Catalyst/Engine.pm line 856
Catalyst::Engine::_ANON_('CODE(0xc07d4d8)') called at local/lib/perl5/Plack/Handler/FCGI.pm line 134
Plack::Handler::FCGI::run('Plack::Handler::FCGI=HASH(0x103aa48)', 'CODE(0xc024630)') called at local/lib/perl5/Plack/Loader.pm line 88
Plack::Loader::run('Plack::Loader=HASH(0x1003e88)', 'Plack::Handler::FCGI=HASH(0x103aa48)') called at local/lib/perl5/Plack/Runner.pm line 263
Plack::Runner::run('Plack::Runner=HASH(0xe06850)') called at local/bin/plackup line 10
at lib/Sql.pm line 294
at lib/Sql.pm line 294"
Stack trace:
line 634 MusicBrainz::Server::Data::Edit
line 77 MusicBrainz::Server::Controller::Edit
line 322 MusicBrainz::Server
line 322 MusicBrainz::Server
line 322 MusicBrainz::Server
line 286 MusicBrainz::Server
Request data:

$VAR1 = {
'query_parameters' => {},
'body_parameters' =>

{ 'enter-vote.vote.1.edit_note' => 'This is a specific thing with some guy singing / talking on top - I\'ve added a work for this, approving to fix', 'enter-vote.vote.1.vote' => '-1', 'enter-vote.vote.0.edit_id' => '18938737', 'url' => 'http://musicbrainz.org/work/ac9eb123-f93f-3351-9a50-97419873719d/open_edits', 'enter-vote.vote.1.edit_id' => '18818457', 'enter-vote.vote.0.vote' => '-2', 'enter-vote.vote.0.edit_note' => '' }

};

URL: http://musicbrainz.org/edit/enter_votes