Every day a box pops up that says Safari can't verify the identity of Facebook.com. I click OK or adjust it so say "Always Trust" and then Facebook.com goes blank. The blank page says access denied, page cannot be found, etc. etc.

All the fixes I've found online seem to be Windows-based and suggest fixing the clock/time on your computer. Mine has always been up to date so that's not an option for me. I've disabled pop-ups as per a suggestion and that didn't do anything.

So if there's any Mac users with knowledge of security certificates, it'd be a huge help.

Using:
SAFARI 5.1.2
SNOW LEOPARD 10.5.8
WIRELESS VIA ROUTER