Interestingly on uTorrent's site I found out why my Azureus not only ran slowly, but completely hung my machine on occasion, and blocked my Internet connectivity.

Linksys routers (mine is a WRT54GS) do some annoying things with keeping connections alive up to 5 days - BitTorrent rapidly fills that space.

So I reflashed with HyperWRT and running the startup scripts recommended on uTorrent helped a bit (also giving me a wireless output power boost for my troubles )

But then I found another piece of advice regarding XP2 connection limitations. LvLKing (I think - linked from the same FAQ as before) offers a patch which eases these limitations, and didn't appear to have any evil code attached (disclaimer: don't rely on my word, check yourself if you want your box to be safe)