There's a few things it can be..
1. Make sure all the bolt o-rings are in good nick, check the the 3 main bolt o-rings on the bolt itself.
2. The hyper 2 reg either needs a clean or the hyper 2 reg piston seat is dented.
That can lead to in-consistancy over the crono.
3. Whats you dell, lpr, hpr all set at?
4. have you had any problems with this before...
matt