Try F9, then right-click and 'Query now' one of your caches in Discovery Services. If that fails, try this..
This site has Gnutella web caches which you can add to your discovery services, I have it bookmarked
Right-click and copy any of the blue links from this page, I sometimes add a couple...
http://gcachescan.jonatkins.com/
Then right-click in Shareaza Discovery Services and select ADD Service.
Paste the link you copied into the Service Address Bar then query it as I said before.