Another reason that you may feel the need to pick it up is that you stay on the old outside ski too long. Instead of moving downhill in a way that allows the skis to flatten gradually to begin the new turn, you stay inside the turn, maintaining a high edge angle from the old turn. Then, the only way to get your skis pointing in the new direction is to pivot that new outside ski and lift the new inside one.
It really depends on the dynamics that are occuring when you do it.
My guess is that you're rushing the fall line portion of a new turn after holding on too long to the old one. The fix is the release. First of all, play with releasing both skis on groomed terrain. I find it easier to do on medium slopes as long as the skier is comfortable there. You can play with a static release (starting from a stop), and then link them.
Another drill that nolo taught at the ESA at Big Sky a couple years ago that has worked really well for my students is "The Waltz". It's difficult to describe, but I'll try: on medium groomed terrain, you're going to draw "W"s on the slope. Start with your skis pointed downhill, pivot them so that your tips are pointed uphill (the middle of the "W"), then you'll start to slide tail-first downhill. Pivot your tails uphill to finish the other leg of the "W". Then, do it again in the other direction.
This drill gives you the sensations of going up a mogul allowing your feel to lead, then moving over the top of your feet and pressing the tips into the trough as you come down the back side of the mogul. I suspect it will help you, as well.