So, i finally upgraded to OS 5.
I don't know if anyone already described the same issue, but anyway:
When in performance mode, changes in the stomps, stack and effects section remain after switching to another slot and coming back to the slot that I edited, even when I didn't store it. Only if I change performance before coming back to the initial slot in the previous performance, the settings ar as they were in the beginning (befor editing anything). So for example:
I'm in performance 7, slot 4 with the delay on. When I turn off the delay by pushing the delay button (without storing), change to slot 3 in performance 7 and turn back to slot 4, the delay is still disengaged. Only when I change to another performance, say to slot 4 in performance 6, and turn back to slot 4 in performance 7 the delay is engaged as it was at the beginning.
Is this a bug or did I miss anything? Maybe I'm wrong but I think that that wasn't the case in OS 4.2...