growl at Jack.Scope

I just wasted nearly an hour trying to find an elusive bug, odd random CPU usage spikes that I couldn't understand at all, I had thought it was the minBlep code I was using but it didn't seem to correlate with high notes, or anything else obvious, then I saw jack.scope was running in the background, killed it and Qjacktl fell below 5% ~ 10% whatever I did,  much better. Okay next problem why does switching from saw to square overload the filter routine sometimes, just get a nasty loud click and then silence, let's see if setting the phase to zero when changing waveforms helps........