Brian this is something that SW team is working on to get fixed. The issue has been seen on Chrome, Firefox and IE as well but sometimes it works on IE. If possible give IE a shot and try your luck.
Yeh I figured as much, the same with Jasons suggestions. But thought I would harass anyway
Try clearing you internet cache / temp files. I had to do that one time with IE to get it to let me back in. Typically I use Chrome.
Portal as been a pain for a while.....constantly having to re-login and even after you login clicking a link will bring up the popup thats says I was logged off and then I have to login again.
I just want to login once a day at the most....a week would be better.