On Mar 2, 2009, at 11:03, Gideon Simpson wrote:

When I put my computer to sleep, and then try to do something with X, I get errors like:

Xlib: connection to ":0.0" refused by server Xlib: Invalid MIT-MAGIC-COOKIE-1 key : cannot connect to X server :0.0

Don't use :0 for display. Look through your environment and make sure you're not setting DISPLAY.