Comment 4 for bug 485727

This is what's happening: When you work in the VMWare, the screensaver timeout expires and gnome-screensaver tries to grab the mouse. Since VMWare won't let it, it keeps trying. Once you leave the VMWare window, it becomes successful in grabbing the mouse and starts the screensaver.

This is a well-known issue that is documented here:

https://wiki.ubuntu.com/DebuggingScreenLocking#gnome-screensaver%20cannot%20grab%20keyboard%20or%20mouse

Since this is basically the same issue as bug 49579, I am marking this bug as a duplicate, even though bug 49579 may not specifically mention VMWare.

Thanks for reporting this issue.