Starting two days ago I have not been able to see any servers when playing COD4 in multi-player.

When I refresh the master server it doesn't do anything. Everything is blank.

Is there a patch for this problem? I did see a system file message that a file couldn't be saved because of lack of space. I have plenty of space on the harddrive. Could it be an issue with the cache being full, and that's why it doesn't work? Where would the folder be located that I need to empty?