Same here, I use the latest version of uTorrent and sometimes Azureus (Vuze) both work absolutely fine, they are not x64 native but Windows x64 editions will emulate x86 to run the older programs.
BTW, in case I am wrong about unsigned drivers being allowed, this is the trick I used to use:
http://news.softpedia.com/news/Disable-Driver-Signing-in-x64-Windows-Vista-53491.shtml