I didnt know they were compatible.
Personally I dont think the motor would re-engage itself, I would be looking for an electrical fault somewhere on the signal that goes to the solenoid that tells the starter to go, like a short to a + bringing in the starter when it shouldnt, or possibly a knacked ignition switch.
If the starter pinion was loose or something it would grind against the ring gear rather than engage itself.
If it keeps doing it then start the engine, disconnect the thin wire to the starter and leave it for a while, or even do this while your using the vehicle (you'd have to do it every time you start up, or stall), if it doesnt do it with the wire disconnected then the starters fine, if it does do it the starters knacked or incompatible.