Mpc2000 as master midi sync, to cubase a slave AND Recording

Mpc2000 as master midi sync, to cubase a slave AND Recording audio
I use mpc2000 as master seq: to play all my 4, Keyboard sound modelers to record there sound on to cubase as audio. But when I turn a midi track on, my Mpc2000, the cubase want work its stop and go and some time freeze. But if i turn off MPC, midi tracks it will sync and run all day.
But you know if I keep my MPC midi track off I will not be able to play and record my keyboard sound. Do anyone know the solution.

had a similar problem with the 4000 and nuendo.
i could use my mpc as master and nuendo as slave but when i wanted to record in the same time i couldnt make the transport REC turn on on nuendo when hitting play on the mpc.
ended up getting a roland vs2400cd and dumping the computer.