I too have this exact same problem after waking from Screensaver on 11.04 (Natty) on an old Dell Optiplex GX620 (P4 HT).
Until this issue is resolved a quicker and easier way of restarting X-Windows (rather than logging into the console) is to re-enable the old CTRL-ALT-Backspace keyboard combination. I discovered this by following Kerry Kobashi's instructions here:
Hi all,
I too have this exact same problem after waking from Screensaver on 11.04 (Natty) on an old Dell Optiplex GX620 (P4 HT).
Until this issue is resolved a quicker and easier way of restarting X-Windows (rather than logging into the console) is to re-enable the old CTRL-ALT-Backspace keyboard combination. I discovered this by following Kerry Kobashi's instructions here:
http:// www.kerryonworl d.com/computers /how-to- restart- x-server- in-ubuntu
Unfortunately this will also log you off but it's better than pulling the plug and doing a cold reboot. :-/
Best of luck people.