As far as I know there are only a few things that can possibly affect your tracking:

1 -- the blades. Make sure that your blades are properly balanced, This is critical.
2 -- the pitch control links. This is where the tracking can be adjusted. check this link for more details: [link]http://www.bladecprepair.com/man_mr_setup_and_adjustment#tracking[/link]
3 -- the only other thing I could think of would be the feathering/spindle Shaft. Make sure that is true.
4 -- you could also double check to make sure that you did not let one of the mixing arms get flipped over. See this pic: [link]http://www.bladecprepair.com/manual_pop/bh_connected.html[/link] Make sure your mixing arms (on both sides) are orientated the way the pic shows.

For this heli there shouldnt be anything else that should affect your tracking.