We are running 2010 on Windows XP and I am seeing an increase of this problem on a daily basis. I played with it yesterday a bit and found that by adding the Select Windows tool from the View-Windows panel on the Ribbon to the Quick Access Toolbar seemed to be a great work around and in so doing actually caused the Window Menu to become functional again. I have put it on 4 different machines so far and it seems to be doing the trick. Additionally, it helps the users get used to the ribbon and QAT and away from the menus and toolbars.
Old thread, but...
I have several users who are experiencing this issue. We have reinstalled AutoCAD 2010, installed the latest SP, deleted user registry keys and so on, to no avail.
Any known fix (not workaround)?
I have a workaround
if I switch to a different workspace and back again the problem goes away. At least it's quicker than restarting ACAD. I use workspace switching in the bar (lower right) it's pretty quick.