Camera Drift Bug in Sequencer

Wonder if anyone can confirm this.

After several playbacks in the sequencer. My camera begins to drift. Not sure if this is because of the crane I have it connected to or what. But it slowly starts to drift on the pan. A little more each time I play it back till the subject starts to go out of frame.

As you can see (hopefully) from the screen shots. That the numbers do not seem to be changing. Yet there is clearly a drift.