Ok, so I know this is a weird one, but every guy on my team is having this problem, so I figured I'd ask, as we are stumped.
We wrap our <WebPartZone>'s in an Atlas update panel. Well, we do, with one exception - the login page does not, because the MS Login control doesn't play nicely with Atlas - long story - for another day.
As you know, each web part has a little dropdown menu on the top right corner.
On the non-Atlas Login page, all the web part menus work fine.
On any other page (and they are the same, except for the UpdatePanel) any web part in the top left corner of the WebPartZone, it's menu won't work. It won't highlight when you mouse over it, and it won't show a menu when you click it.
If you drag the web part to another place in the zone, the menu works. (And the web part that now resides top-left doesn't work).
Is anyone else experiencing this phenomenon?
-Todd Davis
http://www.SeaburyDesign.com