Facebook SSL Certificate
Sometimes when I open safari 5.0.5 and it goes to my home page (engadget) I get a pop up warning (not a pop up browser window) saying safari cannot verify the validity of the certificate for www.facebook.com. It doesn't know if it can trust the signer of the certificate (digicert) but alerts me if I try to visit the site via bookmark, typing it into the url, when I'm not even trying to go to facebook or even when i start up safari. It doesn't happen every time I do one of those but never happened at all before a week ago so I'd like to know what is going on. Anyone have an idea?
I almost forgot I've been using https for a while now and haven't changed the setting recently but I do want to mention that might be a possible cause.
thanks
macbook pro, Mac OS X (10.5.8)