look for this compat-wireless-aircrack-lucid-patched.tar.bz2
it does enable injection for rt2860 ralink chipset but i warn you there is a bug inside
you wont be able to stop the loaded driver!! NOT...

Maybe this could not help you out. But i tried Backtrack 4 R1 recently and rt2860 chipset seem supported or best effort to at least. injection is working on first try only after further attempt...

I was trying too to get rt2860 working it did with the original driver from Ralink but injection is not permit without modding the source code first. I thought i would try the apocolipse rt2870...