Attached below is the correct driver from the Ralink Website. Download Ralink Driver file, extract to a folder and edit the file in
HAS_ATE,HAS_WPA_SUPPLICANT, HAS_NATIVE_WPA_SUPPLICANT_SUPPORT,HAS_ANTENNA_DIVERSITY_SUPPORT from =N to =Y.
If you have not allready done so install the requirements to compile the driver. Specifically sudo apt-get install build-essential devscripts cdbs.
In the DPO_RT3390_LinuxSTA_V18.104.22.168_20100831 directory run sudo make and then sudo make install.
Restart your machine and you should have a device ra0 showing in ifconfig. lsmod should show rt3390sta. If not then edit /etc/modprobe.d/blacklist.conf and blacklist the items shown below. I had to include the rt3090sta and rt2860sta which were drivers from previous driver compilations.