Actually, I am experiencing the same problem with the Twenty Ten theme in Windows XP Professional v. 5.1. When I change the text size in IE, up and down, the menu on the site site mentioned above (https://twogatherbeads.com/) performs just fine. (In fact, the “text size” seems to have no visual effect at all…)
However, when in Firefox, if I zoom out (View > Zoom), the problem occurs as exactly described here: Drop-downs appear under the menu bar, but a little space between makes the drop-down disappear when I attempt to scroll towards it. BUT: I notice that I had “Zoom Text Only” selected in the View > Zoom menu. When I checked that off, and THEN zoomed in and out, the menus worked fine.
From the comments, it looks like nomolos applied govpatel’s 38px suggestion, but again, on that site and mine, I’m still getting that disappearance. Of course, the conditions are highly specific, so I’m not massively alarmed. Still, I’ll keep tuned…
