This is a very peculiar problem. I recently upgraded the monitor I was using for Fedora 10 to a Philips Brilliance 107P from the ViewSonic E70 I had been using. Now, whenever I try to log in, it either shows a completely white screen, but seems to be functional, as I can Ctrl-Alt-Backspace still, or it goes to a black screen, and then takes me straight back to the login screen! The only thing I changed was the monitor. Also, the cursor looks much smaller than on the other monitor, while everything else is the proper size. When I switched the monitor back, it worked again. However, Ubuntu was able to use the new monitor just fine, and everything looks normal on it. Any ideas on why this is happening?