I can't seem to download anything - the website gives me the points for downloading, but the download doesn't begin and the alternative server doesn't work either.  When I try to report it the website verifies that it should be downloading fine.

What am I doing wrong?  I've never had this probelm before, but I tried several games and it's happening with all of them.  I'm not sure what I've changed on my computer in the last couple of days - what could cause that to happen?