Sync Timing Off Please Help !!!!!!

[dizzove]

I have My MPC 2000 slaved to protools and when I start protools the mpc doesn't start exactly on the first bar. I put a empty bar in front of my sequence on the mpc and set a preroll of 1 bar in protools.The mpc starts when I hit play in prootls but not exactly on the one. I have to offset the start time in protools like 1/4/920 and end the 4 bar loop at like 5/4/920 to get a clean 4 bar loop. Is there any way I can get the MPC to start exactly on the first bar so I can record my audio into protools in perfect timing ? If I set the start time at the 1st bar the audio going into protools is chopped a little in the begining.That's why I have to offset the start time earlier to get a clean recording of the audio. I know this is rather long but I'm trying to explain my problem the best I can.

Thanks....
Setup-
Win XP SP2
Protools Mbox 6.4
USB midi to Mpc 2000