>I suppose this is more likely do to some code womewhere changing the mousepointer to an hourglass, which does not disable it. IME, when the system changes the pointer to an hourglass, you can't use it in that app.

yes good point... IME with MMF it does only occur when the mousepointer is programmatically changed by the framework to the hourglass and not when the system changes it. Which is one of the reasons I'm not a real big fan of messing with mouse pointers .cur files.