Hmm... now that *IS* strange... not of my doing, I must hasten to add (and yes, it is I that is normally responsible for changes to the website...)
Since the menu that pops open looks "different" (can't explain, there's just something that feels different about it, other than it's opening in it's own window), I'd guess the graphics department have played. I'll have a wee looky at the script for the menus and see if I can't sort it.
BTW Didimo, 2.0.0.9 is *very* old (in Firefox terms...) Current version is 2.0.0.13, and I would very much recommend you upgrade as both .12 and .13 had major security updates in them.
UPDATE: Fixed, thanks all for reporting the error.