Lion-keep having to input my username/password for forums?

[Imola Ghost]

This has been happening a lot starting today. I've had to log in to Facebook every time I leave and then come back. It's also asking me that on quite a few forums that I frequent. Right now, I can't even log into ATT Uverse online.

Is there something that's going on, that I should fix?

 

[PS65]

Have you checked that Private Browsing isn't enabled? That can cause a similar effect on Facebook.