First of all, try disabling OOB (out of band) searching.

If you're using LW 4 go to tools > options > speed. Untick the box next to 'Enable OOB Searching' > apply > ok. Restart LW.

If you're using LW 5, go to tools > options > advanced > super really advanced > performance to disable this option. Restart LW.


Which version of LW are you using?

You can also try changing ultrapeers that you're connected to. Ultrapeers are hosts that you conect to, to help you with your searches. If you're connected to bad UPs then you may see spam results. Try the tips here: http://www.gnutellaforums.com/263723-post2.html