Yeah, that's normal, if you turn back in too early.
I think what you are doing is cutting out, and anxiously cutting back in too early. Try cutting out, and instead of turning back into the wake, continue to pull out until the rope starts to pull you back in. I'm guessing you are taking a hard cut out, and when you let up, you are actually out-running the boat. You could even try to tone down your cut out. I mean there's no reason to cut out that fast... Unless of course there's a bunch of hotties in a boat on that side!
I wouldn't worry about rope length... As far as I know, that has no effect on your problem. Give what I said a try, and see if that works. Let us know how it turns out.