This is probably a moot point anymore, but I had a problem with the downloader this morning as well.  I have the required ports open in my router, but after just sitting there at like 82% for 10 mins the bliz downloader would say &quot;it appears you're behind a firewall.&quot;  I just let it run forever and at some point it just started downloading very very slowly and finally finished.  My guess is that they had some kind of a problem with the whole process or maybe they changed the ports the downloader is using without advising anyone.