Our application contains many MFC CListCtrl objects with Report View style. When we run our application on a Vista machine, clicking (left or right mouse button) in the list control results in the default beep sound. This doesn't happen on XP or Windows 2000. We build with Visual Studio.Net 2002, and I noticed that this also happens with some lists in that IDE. Our product release date is quickly coming up, so I really need to resolve this soon. Any ideas would be much appreciated!!!