was keyframing transparency on these concentric cirlces (screenshots attached). was working fine with keyframes inserted, but then randomly the shape jumps from center to the upper left corner of the screen...and then a few frames later jumps back..... seemlingly triggered by one of the transparency keyframes. i tried deleting the keyframes in question and it still did it. after a massive undo-undo-undo cycle going back to square one i was able to re-insert the trans keyframes and then it worked fine....
seems to me like a software glitch and i need to upgrade to CC, but i am open to other's input on this. not the first proj this has occurred on.
running a hackintosh with yosemite, adobe 6.0, AE ver 11.0
nobody can tell you anything without proper comp info or a screenshot of the timeline. All you do is make bold and most likely wrong assumptions without giving people any way to see what is going on And respective info.
We need to see the timeline with at least the position properties of the problematic layer revealed. The graph editor may be a more useful display. Just capture the whole thing and drag it into the Reply field on the forum. Select the layer giving you problems and press the U key twice to reveal all modified properties and look for random keyframes.
If the problem is not obvious when you look at all of the layer's modified properties and purging everything doesn't solve the problem let us know and give us details.