Comment 1 for bug 287328

I am also currently affected by this bug in Intrepid. It may have been there last week as well, or it may have appeared in intrepid in the last couple of days. It's bad in that folks could get frustrated and lose their work if they are using gtk based apps where file menus are failing to work. The above is a great description of this bug... but see below for my take on it:

The only thing that I would add is that a single press of the keyboard brightness adjustment combo (Fn + down arrow) seems to register as if the key was constantly down... i.e. brightness goes from 100% and rapidly shrinks to 0% after only one light keypress. The repeated phantom "keypresses" start as soon as you release the Fn key in the combo. For me the brightness heads-up display widget also stays in the foreground on top of other windows.

With these phantom keypresses perhaps the keyboard buffer could be staying filled and this could be causing the keyboard malfunctions and the menus failing to appear on mouseclick? Menus on apps which aren't GTK based still seem to work, perhaps the display of non-gtk menus aren't interrupted by the continual keyboard events?

I am on an Inspiron 640m with intel graphics. I am running Compiz, but this bug also manifests with Compiz disabled.