Well it doesn't really work that well with AH as of now. Meaning it's actually crap with current mouselook in AH.
Which is a bit of a pity because i can remember at least one version of AH where it was great in mouselook, ultrafast snappy yet smooth.
Usually, installing trackIR and setting it up is a breeze, but if problems should arise i'd suggest visit the Naturalpoint site and post the exact problem and system specs. The guys over there might be able to help.
It's a bit of a waste to let it go unused, especially If you've never tried it, you can't imagine what you're missing.