Well with me it was mostly being afraid to shoot enough insulin especially on the lower PSs (due to some lengthy backstory that I will spare everyone! ;-) ) and so I was ending up with a lot of dose changes/seesawing/sliding scale that didn't work consistently, etc., til Terri finally convinced me to try being more systematic with gradual increases, and hold the dose regardless of PS, and that worked really well for Bix.
I have found with PZI that tiny dose changes - 0.1u or even less - can really make a difference. At the point when it came together and I was able to shoot pretty successfully, it felt like there was a sweet spot with the insulin dose. If I could get it right down to the drop the #s would be picture perfect, a drop of insulin too much or too little and the #s would start to shift a little off course in either direction.
Bix's #s somewhat resembled Meatball's when Bix was on dry food, though, and once we switched to LC, for the most part he stopped getting those really extreme highs that made things so tough. I feel a litle lost when I look at Meatball's #s - I see a few places that look like rebound to me, but then trying lower doses backfired, so it's a bit of a mystery to me. But hopefully things will improve for him on this dose!