OK, I gotta chime in here.
if it continually pulls right under accelleration and then pulls left when you let off the gas then yes you did do something wrong. if it pulls for a minute then straightens out then you should be fine.
to test it, find a loose surface like a gravel lot. do a few straight line peel outs then look at your tracks. both tires should have left marks. if its pulling right, then the left/driver side is locking and the passenger side might not be.
did you make sure you had the "gap" in the active spacer on opposing sides. the driver side should be in the back and the pass side should be in the front. this is critical.
did you use the "go-no-go" gage?
did you do the test described in the end of installation?
The no-slip is a great unit. and yes it has some quirkiness. but don't confuse that with it not working right...