AirPort Express music sharing problems

Had my network running great for about 3 weeks, last night itunes would no longer see my shared playlist from my mp3 server upsatirs! Tried everything, unplugged all hardware, reset basestations,

I can acces the internet on the network so the connection is there, Its just itunes will not see my shared music library! All preferences are correct to share music as well.

Any help would be awsome! Thanks guys/girls.

JG

How about Mac or Windows firewalls?

Zone Alarm
Mcafee personal firewall
Internet Security

?????????

k heres one for ye i'm on a network in student accommdation and we are only allowed 1 ethernet address so i put my airport express's so i could use multiple computers if i need but the thing is that i can only see the music sharing feature with ppl who are directly connected to my airport and not on the network as a whole and i don't want ppl on my airport as i have got a complaint about file shareing (which isn't allowed anyone know any way to get around that such as a torpark equilivant for mac or how to overcome a download limit pls tell me)