I would look at your DMX runs and make sure:
A) That you don't have too many DMX devices on one run
B) that the DMX line is terminated at the end
C) If you have a DMXcat or DMX tester, try sitting in a cue/look and seeing if the flicker finder notices anything. You can also view the DMX levels while you see the flicker and see if something is being sent that shouldn't.