Well, since you get an acceptable speed with the magnet link, the problem seems not on your end. It looks like it is connected to the people hosting the file(s).
You might want to read here:
http://www.gnutellaforums.com/showth...wnload+success
And here:
http://www.gnutellaforums.com/showth...wnload+success
And maybe using the patches mentioned in this thread might be useful as well:
http://www.gnutellaforums.com/showth...ht=party+patch 