Very frustrating issue for us. We are running latest general patch release of both OSX Lion, Fusion and VM Tools and have Windows 7 64 Bit running in our guest with Unity mode. All hardware specs are nominal, in fact we have more than enough memory to share between Mac and VM. We have seen this issue on machines with both SSD drives as well as optical drives (Airs and Pros).
The problem is this - when a user has both a Windows app and Mac app running, and the user uses Mac Mission Control to switch from the Mac app to the Windows app, at least 1 time out of 10 the Windows app will not correctly get focus immediately. The Windows app will come to the top of the desktop, and the Mac top menu bar will change to the Windows apps menu context, but the mouse cursor will still be *black* and therefore in Mac mode, as opposed to *white* as it would be when a Windows apps has focus. That means users are clicking inside the app window, and the app isnt responding. My less technical users all assume that this is a performance issue, and they are about to revote over it, but we do not think its performance related sine we have found that you can immediately make the issue go away simply by clicking on the associated Windows app's icon in the Apple Dock - that simple click somehow forces focus to behave. We also suspect that the Mission Control app switch seems causally related, since its the only way we can successfully recreate the issue with any consistency, and though we have had users report they have seen it without Mission Control in the mix we are not sure if thats the case.
The Windows apps that are easiest to recreate trhe issue with are Outlook for Office 2010 and Office Communicator.
Please dont tell me the obvious "dont use Mission Control." I would love to tell my users that, but thats really not the answer and I worry that the buggy mechanism in play here could flare up in other ways even if I went that route.
We have a case open with VMWare support, but they have not really been as responsive as I would like.