Not sure if this is related at all, but I've had a similar problem to the OP for a while now.

On occasion, I'll be running along with my slaves on /follow (via ISBoxer and Jamba), I decide to switch to another toon, so I release the move key (W), then press the "G key" (I have a Logitech G15 keyboard) for the toon I want to become the master and when I do that, one or 2 toons will sometimes just keep running in the same direction they were when following he original master. It feels like I sometimes switch masters too quickly and need to stop moving, wait a couple seconds, then switch to prevent this from happening. It is most annoying in Battlegrounds, where I need to react quickly.