Hello fstz28,
One tip for riding in the mud is to stay back a little on the back and try to keep the front end from sinking in the mud too low. For the problem you described, first you may want to check you tire pressure. Go a little lighter in the mud. However in the woods, you probably don't want to go as low as on a track because of roots, rocks and such. Also, key for me is riding in a higher gear than normal. It keeps you from being in the hard hitting part of your power band which gives you more controllable power to the ground.
Finally, I sound like a broken record today but because this is the 3rd time mentioning the clutch but learning to control your power with the clutch will help you out a lot. Also, remember to stay loose and less agressive when cornering in the mud. Just remember, it's slick for everybody else too. Just slow down at first and ride a comfortable pace to where you're in complete control. Once you get comfortable, you'll notice your speed picks up.
Good luck!!