Pocket Diaper Leakage Problems

For their adorable design, their convenience, and those clever snaps, I love my pocket diapers.  For leaks, I don’t.  It may be that my baby is too small for her large sized pocket diapers, but even when we double stuff them with liners, they seem to have major leakage issues.  The only way we can stop the leaks is to treat them like a diaper cover and line them with a prefold diaper.  I loved them with my older son but he wore then when he was a bit bigger, which may explain our leakage problem.  Does anyone else have these issues?  Are you partial to your pocket diapers or do you prefer prefolds?