@burnout426 And - I was just about to do this when I tried again at Smashwords and it logged me in immediately! I had emailed them about the issue also and they said that they knew the CAPTCHA might be causing users to have login issues and they were working on it. So hopefully it is fixed. I did also again delete cookies and cache prior to it working, so that might have something to do with it too.
Thanks for the help - and the link to the add-on - I'm going to keep that for future reference. All suggestions were much appreciated!