unexpected messages

[Bob Rasmussen]

I just spent a couple hours tracking down a problem that turned out to result
from an unexpected "mouseMove" message on a "hide object" command (while the
mouse button was down, but before the mouse had actually moved).  Not only did a
mouseMove message get generated, but it appears to have preempted the currently
running handler. That's what caused my problem, since I wasn't expecting the
first mouseMove message until after the mouseDown message handler finished. I
haven't found any documentation of this.

More generally, it would be useful to have a summary somewhere of what triggers
system messages, and when. Most are documented somewhere in the Transcript
Dictionary (though not always in detail), and most are intuituve, but this one
caught me by complete surprise. The debugger wasn't helpful due to the need to
trap just after a mouse click. Once I figured out that a mouseMove message was
coming from somewhere (thanks to UmbrellaMan), it was still hard to narrow down
the source, because I kept looking in all the wrong places. Who would have
expected "hide"?

Does anyone have such a list?

RR