Solved Media sharing between XP and Vista(wmp11 both)

Hi,
I was wondering if someone could help me with "Media sharing" between XP and
Vista. I can play media from the XP machine on the Vista machine, but not the other way around. I have tested to connect a another Vista and from that one I can play media and see the first Vista machine.
Is there a limitation here or have I done something wrong?

*i can play media from XP to vista, but not from vista to XP.
*in the XP WMP setting->Media Sharing dialog box-> i can see my vista.
*in the vista WMP setting->Media Sharing dialog box-> icannot see my XP .
with 2 vista machines "media sharing" works great -but not from vista to xp..

the photo is not from my pc's it's only example what i'm writing about

bump!
somebody please?
(the same issue happens with XP [pro sp3]& win7 as well...)

An update: streaming cannot be done:

Sharing files to and from Vista & XP OK
Streaming from Vista to Vista OK
Streaming from XP to Vista OK
Streaming from Vista to XP NO
Media Sharing, Vista to XP

Hope it'll help someone else as well