I don't know why, but this seemingly simple problem is not working AT ALL.
Ok, the scene is very simple. A car, on a path, has to stop and go 3 times around a spline, between 2 points, as you will see.
The problem occurs between keyframes 111 and 153. I can't get it to go the"other" way around. This happens 2 more times, but the keyframes are only 1 frame apart that you don't notice. The rendering engine that I use looks between the frame and still renders it going backwards, only at super-high speeds.
If you can get this to work properly ... THANK YOU!