I just recently learned Continental knitting from Amy's videos since I'm left handed and thought it might be more natural. I love it, made my stitches much looser and more even...but I do still find purling somewhat awkward until I get into my groove. Here's what I do to work the yarn:
Assuming you hold that working yarn like in Amy's video (wrapped around the pinky and then the index finger), I basically take my thumb and middle finger to pinch the yarn, pull it down and wrap, and hold it there or push it wherever it needs to go to get the purl stitch thru. It's probably more work, but I was having the same problem with stitches falling off and this fixed that...and it's become a pretty smooth movement for me. Hope it helps!