Comment 23 for bug 91192

http://rt2x00.serialmonkey.com/phpBB2/viewtopic.php?t=3509&postdays=0&postorder=asc&start=45

The RT61 "Enhanced Legacy Drivers" version nightly has been working stable for me for over a week. (The driver that shipped with Feisty would lockup my machine after less than an hour of heavy usage)

The Daily Build can be found here:
http://rt2x00.serialmonkey.com/rt61-cvs-daily.tar.gz

You'll need the kernel headers, gcc, and the usual suspects (gnu make, etc) in order to compile it against your current Feisty kernel--but it works and when you're done you wont have to reboot your PC every 10 minutes because of a buggy network driver. (make sure you remove the old rt61.ko module first and then do a "depmod" after compiling and installing the new one)

Hope this helps,
- Jeff Rousseau