Vista - Cannot view shared videos

The configuration is:
1. Desktop with alot of Movies\Music
2.Laptop
3.Wireless Connection for Laptop, Cable for Desktop
4.Vista Ultimate on both

I turned and configured "Media Sharing" on both my computers and i can view
each other library on Media Player (Although on the laptop, the "Media
Sharing" feature on the "network center" is apperantly off its still works
for streaming music and viewing the thumbnails on videos)

I cannot play almost all of the videos from the desktop for some reason
(Some are encoded with Xvid, some not)
I say "Cannot", because once in a while, one does get through. i don't
think it's a connection problem because i can open a shared folder in
explorer and Double-Click on a video file and it will play ok, there
something wrong with Media Sharing's Streaming Video


--
Or Tsemah
YSIDE