Well, I don't think its the OS that's freezing Gnotella, its Gnotella itself. The freezing thing is common, happens to me too. But the thing is, Gnutella works on transmitting messages (searches and such) and what I've noticed is that Gnotella freezes because of the amount of messages your comp has to process.. Watch, if Gnotella is freezing, go to the Hosts page and right click in the window and say Disconnect from Network and BAM no more freezing. Whats interesting is that other Gnutella i've used (LimeWire and Bearshare<--before it became spyware) doesn't have that freezing problem so it seems that it probably is a Gnotella-specific problem, which will probably be fixed in the next version.

Oh and if you hate Windows... stop using it. You can always go the Linux route. Cheaper too.