Similar problem to others posted here. Widgets won't drag in the appearance/widgets page. Cursor changes correctly when over the widgets, but when you try and drag, it selects text instead.
Have tried the screen options workaround: screen options doesn't even activate.
Tried both Safari and IE browsers on Mac and Windows OS. Problem persists.
All plugins have been removed (not just deactivated). Problem persists.
Reinstalled WordPress. Problem persists.
This is a box stock installation on a separate domain from our main website, doing nothing but running wordpress. Any other ideas about what could be causing the problem?