The only thing that I can think of that may cause the problem is OPEN GL acceleration. Try turning it off.

If that's not it, then I need a lot more info about the project, like a screenshot. There's nothing about motion blur that would change orientation or position of layers. There are a bunch of other things that may cause this, but without looking at your comp I would only be guessing.

Show us a shot with the motion blur turned off at the same point in time so we can see what is fouled up. It's hard to see here. I can only see one layer boundary and what I assume is a null. . I can't see all the layers. I don't see a null in the timeline. I'm assuming you only have 1 camera.

That's really confusing. Is there a chance you could post the project as a zip file? Don't need footage, just the .aep

There are a bunch of sites where you can post files for free. DropBox gives you about 5GB of cloud storate, You Send It is another service. There are a bunch.

OK, here's my best guess. When you turn on motion blur time samples differently. The keyframes that are causing the problems are at a z rotation for the camera of 179º. This made me think you were experiencing a gimbal lock with your camera moves. When the camera gimbal locks the camera orientation flips. It has nothing to do with motion blur being enabled on the layers.

I seldom apply tracking data directly to a camera for this reason. I almost always apply the tracking data to a null then parent the camera to the null. This will prevent gimbal lock problems with the camera.

There is a solution that may work for you. Open up the composition settings, the Advanced tab and change the Shutter phase to 0º. This should prevent the gimbal lock that you're getting. I wouldn't call this a bug, but a better workflow would have prevented the problem in the first place.

I can't imagine that changing shutter phase would cause a crash. Make sure the Optical Flair plug-in is updated to the latest version. It's known to have some serious problems before the update. Also, make sure that AE is up to date.

If that doesn't do it make sure that you're purging frames. The setting is in the Secret preferences. You access them by holding down the shift key while clicking on Preferences>General. Then click on the bottom option Secret, and purge every 3 or 4 frames.

The last suggestion, without moving all of the keyframes for the camera to a null and using the parenting trick would be to delete the keyframes that are causing the problem and returning the Shutter Phase to -180º.