I haven't tried removing any pre-sequence info from the pattern to see if that makes a difference. When changing patterns though, I've given the machine lots of time to load the new pattern, i.e. I've pressed the relevant button long before the end of the pattern. It could still be that something is getting confused when loading the pre-sequence info, but at least it's not because the machine barely has time to do it because I tried to switch patterns too near the end of the previous pattern.