We're going to upgrade to vBulletin 3.6 soon (hopefully the week after next). I don't know if this will solve the problem, but it's not worth spending a lot of time to fix right now when updated templates are available from Jelsoft. If it still happens after we upgrade, we can spend more time trying to resolve it.

However, if you (or anyone else) wants to try and figure out what's causing this, feel free. I'll be glad to implement a temporary solution, but I don't really have time to do layout troubleshooting right now.

A quick check indicates that the table cells in question have a fixed width specified in the XHTML code (175 pixels). I know Opera, at least the latest version, is supposed to be very good in terms of web standards adherence, so there must be a good reason why it is ignoring that specified width.