the attached project has only one operator, playing sustained single note with one oscillator's envelope looped: i have crashes if scrubbing on arranger every time the note is sustained
the same with other type of loop envelope, not just beats.
http://www.beatbank.it/tmp/bugs/scrubbing.zip
the file also contains some bug snapshots created after the crashes.
i tried reproducing this by making a new operator patch, but i wasn't able to. so i stopped (really need to have some things done now
hope this helps in some way
cheers