"value_changed" for vadjustment

[Allin Cottrell <cottrell wfu edu>]

I'm trying to figure out what internal GTK mechanism is sending the
"value_changed" signal for the vadjustment on a gtk_scrolled_window.
I've got code that is designed to "catch" the vadjustment at the
point of "size_allocate" for the widget, and set it to a sensible
value (that is, the window should not necessarily open up with the top
of the contents visible; typically it should be pre-scrolled down
some).

I put a debugging watch on "value_changed" and I can see that my code
is doing what was intended, e.g.

"Got signal: vadj value now 290"

But this is immediately followed by

"Got signal: vadj value now 0"

before the widget actually appears.  The second value_changed (unlike
the first) is not coming from any explicit call to
gtk_adjustment_set_value in my code.  How do I track it down and stop
it?  Thanks for any help.

Allin Cottrell.