Comment 18 for bug 107115

me too, it also occurs when swichting to say tty4 and then trying to switch back to tty7
Feisty @ 2.6.20-15-generic i686
GeForce Go 6800 Ultra
nvidia driver
in most cases i can still see my mouse pointer

workarounds:
- sometimes pressing ctrl+alt+l, pressing a key, entering my password and pressing enter brings up my desktop again (does not always work)
- without beryl active, there's no more black screens (for me)