when it comes to the rt2860sta wireless card debian.org states that
It is present in Debian kernel images since 2.6.29 (i386, amd64).
also
Firmware has been removed from the driver in Debian kernel images as of 2.6.30.1 It is available in the firmware-ralink package since version 0.17.
Unfortunately drivers from firmware-ralink don't actually include working drivers with wpa support.
At the time this article was written, drivers from http://www.ralinktech.com/ are broken and difficult to find. You can get a copy of the tweaked drivers here: http://ticcaso.fileave.com/wifi.tar.gz
Extract the archive. (preferably in /home/username/bin/wifi so you don't move the files around because for some reason if you delete that folder the drivers wont work anymore)
Open a terminal and move to ~/bin/wifi.
The default installation doesn't have the linux headers needed for compiling stuff so you will need to install them first:
sudo aptitude install linux-headers-2.6.32-5-686
Change the version to match your system.
Then run this command to build the driver:
sudo make && sudo make install
After some time you will get a warning, however it can be safely ignored and then it should still succeed.
Now check your wireless interface by running:
sudo iwconfig
In the case iwconfig doesn't work, try ifconfig instead.
Once you have identified your wireless interface (usually wlan0 or ra0) run these commands:
sudo ifconfig wlan0 down sudo rmmod rt2860sta
Now type Alt+F2 to get gmrun and run:
gksudo thunar /lib/modules
Enter whatever your kernel version is, go to /kernel/drivers/staging/rt2860, and rename rt2860sta.ko so you know its a backup.
Now copy the compiled driver from /home/username/bin/wifi/os/linux/rt2860sta.ko to /lib/modules/2.6.32-5-686/kernel/drivers/staging/rt2860/rt2860sta.ko
sudo cp /home/username/bin/wifi/os/linux/rt2860sta.ko /lib/modules/2.6.32-5-686/kernel/drivers/staging/rt2860/rt2860sta.ko
Return to the terminal and run these commands:
sudo depmod -a sudo modprobe rt2860sta sudo ifconfig ra0 up
and you should be done.