JJOS XL Version 3.53 FREEZING/STUTTERING / MPC 2500

hey..... first time posting on here, hope someone can help me out, I've made a beat, eight bars long using 5 tracks, samples, kick, snare and hats. then i synced the MPC to logic, now the beat freezes and stutters on bar 1 for a few seconds then jumps to bar 3 and plays as normal, this happens when loop mode is off and on, and also when the MPC is standalone.
has anyone else had this problem and is their a way around it,
thanks

AFAIK this only happens when there is a MIDI loop going on... but you said it's also standalone (maybe you already recorded such a loop to seq, so look into step edit)