How many turns were on the drum when it slipped, and were any of them crossed? The cable end clamp is not supposed to hold the cable when winching, only when spooling on. If you had half a dozen turns on there and it still slipped try roughing up the drum or applying non-slip paint.
Use friction rather than a dab of glue - its worked for generations.
Also, synthetic ropes are designed to operate with the rope crossing over itself - the opposite to steel ropes - to keep it from slipping.
Stu.