I've a similar issue as someone who posted a while back over here. I've tried everything suggested (even the part that apparently gets it to work for this guy) and nothing works.

I'm positive it's not a compatibility issue as the manufacture I bought it from confirms this unit should work with injecting.

snippet from their website below - http://www.danets.com/turbotenna/LinuxSetup.php

Patch Driver Installation

Here comes the insteresting part - the patch driver for packet monitoring and injection.

Although it is intended for verifying that the hardware is capable of injection, we found that it has good stability in working with the aircrack-ng suite.

Those who failed to install the patch driver with compilation errors probably forgot to update the OS (operating system) before continuing.

So, the first thing to do is to open the command line window at Ubuntu and update the OS and the "IW" package for configuring the Linxu wireless device.

The Kernel 2.6-28 was used to install the patch driver. As Linux is an Open operating system, it is being updated by many other parties in such a way that compability might not always be warranted with new release. Hence, it is important to install the update against this Kernel release to make sure that it is compatible with the patch driver.

While the antenna is physically connected to the USB port of the computer, disable the wireless adapter. You could do this by right clicking the wireless icon at the top right hand corner and select disable.

Ignore the Ubuntu update window that pops up from time to time, Or, simply disable the automatic update.

Download the patch driver, blacklist the existing wireless drivers before executing the installation.

sudo make
sudo make install

See also the tutorial:

http://forum.aircrack-ng.org/index.php?topic=5755.0

You may then be able to test that injection is working.

I am running backtrack 5 on VMware Workstation 8.0.1. Since I am not using ubuntu as described above, I assume the patched drivers are already installed? I'm an absolute beginner to linux so I may be overlooking very simple here.