Couple of minor issues with the HTML on that page:

• The label columns should be top-aligned, especially "Type:" and "Attributes:", otherwise it's hard to see what they are labelling.
• "Attributes:" has a superfluous <label> around it.
• "Begin date:" and "End date:" have <label> with a for attribute around them but the ids being pointed to don't exist. They should probably point to the field for the year, so "id-ar.begin_date.year" and "id-ar.end_date.year".
• The textarea for the edit note should have an id of "id-ar.edit_note" rather than "ar.edit_note" (at the moment the label points to the former so it doesn't work).
• Looking at the instrument attribute in my browser (FF 3.6.15 on Ubuntu/Gnome) there is no space between the drop-down menu for the instrument and the button "Add another" (see picture). I think there needs to be a bit of space there, maybe as much as there is below the button.