Looping (repost)

Hello.
I think I know exactly what you are talking about, as my XP-80 did the same thing. I am pretty sure now that it is the polyphony (64 on both). I had read something that fixed the "hiccuping" problem on the XP and should work the same for you.
In your Edit menu, look for "Shift Clock". This will shift the sequencer clock on whatever parts you would like to the specified amount, so that everythings not being triggered at the EXACT same time! What I do, you may find a different method, is shift the bass & drums -1, piano, rhodes, or any other keyz +1, and leave any other filling parts (strings, brass, leads) on 0 (basically, DON'T TOUCH THEM). Your loops should sound nice and tight after this. Hope this helps!

-Austin