I have a custom morph that overrides handlesMouseStillDown: to return true.

Simply by doing only that, it causes
WorldState>>#drawWorld:submorphs:invalidAreasOn: to send
#fullDrawMorph: with my Morph as the argument on every MouseMove event
over my morph, regardless whether any button is down or not.

I only noticed it because the rapid redrawing causes a slight
flickering in my Morph.

Setting handlesMouseStillDown: back to false, my morph's redrawing
code is not executed at all when I move through it.

I have no idea why simply handling this event causes the rapid redrawing.

Thanks for any suggestions..