Cassie, I have Firefox but changed over to Internet Explorer 9 and encountered the exact same problem.
I, too, went into my history and clicked on a link to a discussion group on which I posted recently--so it took me back to where I was already logged in.
Ahhhh, great minds think alike. LOL
Age 67, 5 feet tall
Highest weight ever in the fall of 2010 246 lbs.
FitDay starting weight 1/17/2011 240 lbs.
Weight 3/26/2014 223.4
Current weight 4/4/2014 221.2