Hi again Henri,
Funny you should mention that, I was pondering that a bit already. I'll keep my eye on it to confirm, but I can only ever remember that happening either with sculpties or mesh being involved. It doesn't happen with a particular edit operation, sometimes all it needs is camming the object being highlighted or moving it.
Hmmm, I wonder if it might simply be related to rendering the beacon?
Love,
Lia