There is a logic in the OScopeCtrl using a timer to prevent permanent rescale and redraw when the window is resized. This logic was broken, and I fixed it. Looks like it has undesirable effects on Mac.
Let's try something else. Does this work too (with the line from above present again) ?
Index: OScopeCtrl.cpp
===================================================================
--- OScopeCtrl.cpp (revision 9642)
+++ OScopeCtrl.cpp (working copy)
@@ -527,7 +527,7 @@
bRecreateGrid |= bInvalidateGrid;
// To prevent startup problems don't start timer logic until
// a native OnPaint event has been generated.
- if (m_onPaint) {
+ if (m_onPaint && IsShown()) {
bRecreateAll |= bInvalidateGraph && bInvalidateGrid;
timerRedraw.Start(100, true); // One-shot timer
}