Comment 98 for bug 709461

I'm having this problem also after updating to 11.04. I also have an nvidia graphics card. I've install the xorg-edgers ppa and the small button sized masks have been replaced with a desktop sized mask. I'm running Ubuntu Classic. It seems to happen after the computer has been running for a while. I'm guessing that it might be related to the Update Manager.

Symptoms:
Mouse moves but I cannot click on anything (entire desktop). I have not tried using another workspace.
Keyboard works fine.
Hovering over hyperlinks also doesn't change pointer to the usual finger, as if the hyperlink isn't there.
The same goes for hovering over buttons in an application, they do not respond with the typical visual 3D effect.
xwininfo reports "Error: Can't grab mouse."