Mwahaha... I defeated the pocket!
I had to do it about FOUR TIMES, but in the end I successfully made a pocket that actually holds stuff and isn't a big old saggy mess. It's a moderately sized mess, and I'm fairly certain that no one but myself and possibly my Dad would notice. (That's right, Dad, I KNOW you always look for loose threads on anything I show you!)
Now I've got to do it again *thumps head on desk*