I've a suspicion you didn't see the link I gave. There it points out that the most popular files on the network are often corrupt, particularly if they come from T3 sources. Yes it appears the RIAA is trying to kill people's enthusiasm for downlding music & sharing it.
Instead of downlding from T3 sources, see if you can get them from other sources such as T1 or cable or modem.
Also re: video, get VLC:
http://www.videolan.org/vlc/ (choose nearest mirror site) & see if you can play them with that program. If you can, it means you dont have the appropriate codecs for some video types. Have you seen
Movie download issues & also
CODECs list and alternate players for Movies