How are you connecting (56k, cable, DSL, and so on)? Your ISP could be blocking file shareing or Gnutella. To find out you need to contact them. And if you use AOHell don't bother, because their ultra-crappy customer service will not help at all. (And if you are useing AOL 9.0 there is a firewall embedded in that look here for more information:
http://www.gnutellaforums.com/showth...threadid=23895
Good luck.
deepblue