Could be...are you using a patch to increase connections? There are a couple, I used the M$ one but I think more people use the other one!

http://support.microsoft.com/default...5bLN%5d;884020
http://www.lvllord.de/?url=tools

and another link with an update about the lvllord patch...read before downloading anything, since I haven't used that one I'm not too sure about it
http://www.gnutellaforums.com/showth...ighlight=patch