I was having so much trouble trying to do exactly what I wanted with the combo that I gave up and started over with a combo in listbox mode (style = 2).
This works pretty good though I still have to tolerate the fact that the incremental search is a little flakey, but increasing the _dblclick interval to 1 second in the getfocus (and returning it to nominal in lostfocus) seems to help.
Still, one of the questions I still have from all of this discussion is:
Suppose I use a combobox with style = 0. With FIELDS as a rowsource, it's not possible for a user to enter an illegal value from the list, but it's still possible to enter an illegal value into the combo's textbox.
The valid is the natural place to detect an invalid entry, but if an invalid entry is detected, what is the proper way to restore the combo to its state just prior to the user's entering a bad value?
"The Iron Fish: The water is cold...but the fish don't mind"
...Jay Jenks, boyhood chum