Presuming everything else is fine, you've received subscription confirmation, have a username/password, etc. The trouble almost always has to do with a corrupt cached file in Internet Explorer's cache directory. This is a very, very common problem with all browser and the following procedure should be done ocassionally anyway to avoid further problems.
By the way, "cached" or stored files, are used by the browser to "remember" what the page looked like the last time it was there. This is done to speed things up. If that page has changed, which of course it does a lot at TGF, the poor thing can get confused. That's why you need to clean out these files from time to time.