MackieControl & Xtenders not working right
 

Hello,
When making mix moves in ProTools 7.4cs2 with my MCU & (2) Xtenders (in HUI mode), the faders sometimes delay and sometimes do not move correctly.

Sometimes I make a move and they go back to where they originally were.
I am using a Unitor 8 mkII interface (although my Edirol midi interface had the same results).
Is there a midi setting I could be missing?

Mac G5 dual 2.0 with 4 gig ram, OS X 10.4.11, Mbox Pro firewire interface.