O.k. so here's my first query. I wrote and app that works fine under Leopard - I push a button and see a cellular automaton (CA). But under Snow Leopard and Lion, the CA doesn't get drawn, unless I hide and unhide the app. No console messages are emitted. Any clues as to where the fix is? Could this be the result of some bug in my NSView initialization that was not exposed by Leopard, but was by Snow Leopard? Thanks. altenber@hawaii.edu