This happened with FireFox, version 3.6.17 while adding a new release for Devine's Jug Band.
When creating a track list (http://musicbrainz.org/release/add#basic) , I got "A track name is required on track #" for every track.
I tried every option that I could find.

In the basic track list editor by just pasted in the following:
Fourth Street Mess Around
The Dallas Rag
Hop Scop Blues
Terrible Operation Blues
Ted's Stomp
Spider's Nest Blues
The Donald Rag
Too Long
Sadie Green
Beaver Slide Rag
Rufus Rastus Johnson Brown
Jackson Stomp (Cow Cow Blues)
Low Down Blues
El Remolino
The Lindberg Hop (Overseas Stomp)
What Makes My Baby Cry

I unchecked the option 'Track names start with a number". Result: errors.
I tried adding track numbers to the text and checking the option 'Track names start with a number". Result: errors.
I tried advanced track editing. Result: errors.

No matter what, I always got an error per track: "A track name is required on track X".
The most irritating thing was that, after getting the error, all my work was undone and every track was named "- Devine's Jug Band"