Sometimes mouse cannot be used on applications

[Antonio M]

Sometimes I have a very strange behaviour of mouse.

I cannot use it on applications in Gnome, but it works on main menus (I 
mean the top line on the screen): if I log out and then I login again 
everything is working fine for a long time.

I have no idea how to help to debug it - I filed also a bug
https://bugzilla.redhat.com/show_bug.cgi?id=951922

My system is a standard updated Fedora 18 using intel driver. This 
behaviour started some time after some update but I have no idea what is 
driving it.

Tnx