Sharing files on a home network: problem!

[4rock]

HI! I have a couple of computers connected to a wireless network, and I like to be able to access my songs on the network (I only download my mp3's on the host computer, but share the 'my music' file with the other computers on the network. Recently I've been downloading songs that can only be accessed on the host computer but not on any of the other computers on the network. I'll get a message like: 'windows media player cannot access this file' or 'link not available' (Real player). What's going on? Are these mp3's encrypted so I can't share them on a network? I never had this problem before! Any help would be appreciated.

[4rock]

Anybody???? This is really weird, since I checked all the settings on my computer and they're still all the same. The 'my music' file is being shared, etc. This seems to be a problem with the mp3 files that I downloaded. Like I downloaded something more than just an mp3 and something's running in the background. Cause if that file is in use on the host computer, I can't access it with any of the other computers. Am I being paranoid?

Oh, and what does the little black dot on the envelope next to my thread mean?