screensaver password fails first time, every time!

[John Aldrich]

Just wondering if anyone here has seen this behavior... I lock my screen 
when I get up (Fedora 15 running XFCE and Xscreensaver) and when I come 
back 99.999% of the time, I have to try twice to unlock the console. I 
*know* I'm entering the password correctly, but it still comes up as 
"authentication failed." If I immediately turn around and try again it 
works. Same password, just a second attempt.

Any ideas?