One of our users experienced this issue in Windows 7 64 bit. It happened to other users who logged into the system also so it wasn't a profile issue. After trying numerous steps from other posts and this post we finally installed IE9 and that resolved the issue. The one thing we didn't try was to Reset Internet Explorer Settings prior to the IE9 install so I'd be curious if that solves anything. We were ready to rework the system if this hadn't worked.