Anyone using a PFC throttle quad with the 744?

I know a couple of you guys are using this Precision Flight Controls throttle quadrant. I have one with the 4-engine control attachment and have a problem. When on finals with the 744, I like to click off the A/T and A/P and fly her in manually. The problem I have is sometimes the queen does not relinquish control of the throttles to me. I have control over everything else but the throttles. I can see on while in the VC that the throttles are acting crazy and going up and down very quickly. I have to sometimes re-engage the A/P and autothrottle and then deselect them again to regain control. Does not happen with other payware stuff. Any ideas?