Hi,
one possible explanation could be, that the position of the physical amp knobs (Drive, Bass, Treble etc.) are at a different position than what is programmed into the patch. If for some reason the pod thinks that you have moved one of the knobs, the amp setting in the current patch jumps to the value of the physical knob. This can even be triggered by vibrations. I think this is referred to as "knob jitter".
You can avoid it by turning all knobs to zero and then reloading the patch. It seem that this problem does not happen in the zero position (at least it hasn't for me).
In order to verify if this is the problem, you can call up the amp settings screen (select the amp block and double press ENTER) in the POD and look if one setting differs from the original position which is marked with a dot.