score list vs xfire

Hi. Just started playing 2 days ago, and yesterday joined a clan and started talking in conference on xfire. When i start playing, and want to press tab to see the score sheet... nothing happens. i restarted the game like 3 times and nothing happened.
after leaving xfire... the game went back to normal and tab was working again.

Can someone tell me if this is fixable and how to fix it? Tks for your time.