Google Groups bug

I'm using Firefox 3.5 on Linux. Everything was fine until today, but
now the right-hand-side interface suddenly appears on the left,
covering the messages and preventing navigation. I noticed this on two
different computers. I wanted to report a bug to Google, but didn't
have much success. Their Help Center only shows FAQ, and googling for
"report a bug in google groups" or similar terms doesn't yield
anything.

I'm sure I'm not the only one with the problem, but how to we get
through to the Google?