I Can’t download nothing

Help!!!!
I‘ve Limewire 4.8.1 pro and lately even though limewire is connected (turbo charged) I can’t download any file. A popup appears saying that the file is corrupted and I click yes to go on downloading the file but nothing changed, because it appears that the central computers are busy or that I need more sources.

I’ve Windows XP SP2 and the firewall of windows is activated, I‘ve Sygate personal firewall pro too.

But I think that all began when my antivirus was updated to avast 4.6 pro.

I‘ve followed the instructions of the FAQ of limewire for users behind a firewall but they don’t work.