Freezes when opening right-click menus or tooltips

[Francesco Mazzoli <f mazzo li>]

Hi,

I was unsure on whether this is the right venue, but I didn't have
this issues on gnome apps before I started using gnome-shell.

The problem I'm having is 1/2 second freezes of the whole desktop on
when right-click menus or tooltip appear.  This happens in Google
chrome, firefox, evince, gogglesmm, and probably others.

The problem is not present as soon as I log in and only shows up after
several hours of usage.  It renders browsing almost unusable.

I'm using debian testing with the latest packages installed,
specifically gnome-shell version 3.14.2-3+b1.

Any hints?

Thanks,
Francesco