Yeah, brush speed sorry, but it don't crash more, as I said before, even after hours of work, with different brush speeds.
About the compulsive crashes, we know about that, but Noggit is not as perfect as WoWEdit.
I'm sure the team do their best, but they are humans (Blizz dev too ? Hum ... not sure ^^), so maybe it'll be perfect someday, but until that, we have to live with it =)
We can only report bugs to help them to make Noggit better =)