I today updated to lucid lynx beta and had this issue. I managed to fix it by compiling the latest driver as others have described above, however I also had to copy the new driver from the directory that make install put it in to the /lib/modules/2.6.*/kernel/drivers/staging/rt2860 directory. After a reboot it is connecting over WPA2 at 270Mb/s (apparently)
I today updated to lucid lynx beta and had this issue. I managed to fix it by compiling the latest driver as others have described above, however I also had to copy the new driver from the directory that make install put it in to the /lib/modules/ 2.6.*/kernel/ drivers/ staging/ rt2860 directory. After a reboot it is connecting over WPA2 at 270Mb/s (apparently)