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 68, 5 feet tall
Highest weight ever in the fall of 2010 246 lbs.
FitDay starting weight 1/17/2011 240 lbs.
Weight 8/14/2014 lowest in a long time 224.2
Weight 9/23/2014 doctor visit 233
Weight 11/14/2014 228.8