Stumped & Frustrated..Advice needed! No media files will play!

Good evening and welcome to my most annoying week! Here goes - I've been using P2P for sometime...always been able to solve the on-going problems that arise evey now and then, however since using Limewire it seems that 'NO' media files (.avi - Divx Xvid compressed etc, .mpeg, .mpg) will play! Now when I say will not play I don't mean 'XX codec needed', the problem I think is stemming from the duration of the files. The duration of the files after downloading are '00:00:00'!! Ive checked these files with 'Gspot' which says they can be played. I'm completely up together with all codec's (Nimo, Xp codec pack, Morgan & ACE mega) and players (Playa, VideoLAN etc) but still no joy! The files seem to play for a split second then stop! 'Gspot' says file is ok but then says XXMB is extra garbage (the XXmb is always the full file size!!)

Can anyone shine any light on this ongoing problem?

Thanks for your help

G