Sorry that you've had problems with your pitch factor.
The startup symptom may be caused by a faulty nonvolatile memory. We've only seen this once or twice but it's possible. When the PF powers down, the currently loaded preset and its values are saved to memory. The memory could be faulty or the circuitry that detects powering off could be defective.
I don't know what could cause the sound to evolve over time unless there's feedback happening somewhere. I'm sorry to say that I cannot account for the MIDI logjam either but I'll check with someone who knows more about this.
Greg's suggestion is a good one. It would help us if we had a better sense of what you're experiencing.
I have to say that we have lots of folks using our stompboxes on the road and, while admittedly nothing can be perfect, we do everything we can to make a reliable product.
BTW, I checked out Spidercapo and its cool.