Bill's right, the reason you're sliding out is because:
A) you're throwing it off the wake, in which case try to wait. The way I've told people to remember is to not let go with your front hand until you would normally grab the board on a regular wake jump.
B) you're landing on your HS edge. The easiest way to correct this is when you're landing, point your lead hand down, almost like you're giving the thumbs down signal. This will push your shoulders over the TS edge of your board which will help you ride away from the wake.
One more thing, make sure you're rotating the full 180 degrees, go past where the board points at the boat. You'll get it, once you do you'll wonder what the big deal was...