Just placed two pictures without incident and am pretty sure you nailed it even though it's not much of a test... the way I was doing it prior, one of the two attempts would have crashed it, so I think we're clear. I'll revive the thread if needed, but it looks like we can consider this problem
solved and chalked up to user error.
My copy of Sigil thanks you for schooling me on how not to make it choke.