Animation drift

Hi, I'm a beginner, and using Qavimator. I'm working on an animation that's having a puzzling problem: parts of the body slowly move when they shouldn't move at all. It's a seated animation. For some reason the chest turns a bit to the right, and (less problematically) the legs wave a bit. When the animation starts, *every* joint has been moved at least a little bit, and in fact every joint moves during the animation. Priority is set at 4. So that should eliminate the usual reasons for animation misbehavior. But the drifting occurs when the figure is either mainly or almost completely motionless, at least according to Qavimator. Any ideas?

Hm, check the BVH file, the first frame should be the reference frame, which should have nearly all zeroes, only the second value for the Y Position of the pelvis should have a value.

For example:

MOTION
Frames: #
Frame Time: #
0.000000 43.528519 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000
... < other frames >

Unfortunately that doesn't seem to be it. Frame 1 was already at 0 throughout, and Frame 2 had every joint moved. I tried your suggestion to change the hip position in Frame 1, but it made no difference, the anim still drifts.