the title of your post says.......
but this is the backtrack forum. I'll assume you are indeed using ubuntu.Injection-problem with AWUS036S rt73 Ubuntu hardy k2wrlz 3.0
I had massive problems trying to recreate what you can do easily on backtrack in Ubuntu. Are you trying this in Ubuntu? Backtrack has all the best wireless packages and patches specifically set up to be very compatible with most wireless cards and chipsets. What happens when you try the same thing on backtrack?
If you want to use ubuntu have you tried grabbing the latest patches etc from the aircrack site? here's a link
this guy also mentions getting it to work on gutsy.