Intermittently, after switching away from VMWare Player, it is not possible to get focus again, and the app/GUI is unresponsive. Mouse pointer can be a hand, hourglass, or arrow pretty much randomly from one occurrence to the next. This is on Windows 7 Home Premium. Currently VMWare Player 6.0.3, although the problem has existed on earlier versions. The guest OSes happen to be Ubuntu 12.04 and 14.04.
This is not a question of mouse focus on a VM or guest OS issue. The VMWare Player application itself becomes unresponsive and does not take focus. If I try to alt-tab or minimize other apps while the VMWare Player app is not minimized, the title bar of the app stays grey. If VMWare Player app is minimized, the window will not be viewable until at some point VMWare Player decides to become responsive again. That can take 30 seconds or 30 minutes or longer.
The condition can persist through Windows suspend/hibernate. It seems like power-related events such as lid close, display off, etc. may be a factor, but I am not sure. The problem happens frequently sometimes (like minutes apart, even with no power-related events), and other times many hours or days will go by without issue. It seems like the guest OS continues to run even while the VMWare Player app GUI is unresponsive. Although the way I use the VMs, usually nothing is happening visually so one would be able to tell. One of these days I could try to SSH into the VM to verify this.
I have tried to search for terms like "vmware player cannot get focus" or "vmware player not responding". But I do not find any references or reports that look like the same issue.