My PS3 sees and works great with PSM. My Xbox used to, then I upgraded. At first I could still see the server but then I'd get an error that it couldn't play the specified file type. I installed some additional codecs thinking that would fix it. Now the Xbox360 can't even see PSM, it doesn't show up as an option. It still works on the PS3 just fine.
My Xbox can see file shares on the same computer and get out to Xbox Live, so it doesn't appear to be a network issue. Any suggestions?