Windows XP ComboBox bug when using "Windows Classic Style"

[jrho...@hotmail.com]

I found a very odd bug while developing a Forms app with Visual Studio
2003. If you have a ComboBox with no items in it, when you click the
arrow, an empty drop down list is displayed which is the height of 1
item. In Windows XP, this all works fine if you have your "Windows and
Buttons" Display Setting to "Windows XP Style". However, if you change
it to "Windows Classic Style", when you click the arrow in your
combobox, it does not show the empty drop down list. Worse yet, the
system "thinks" it is displayed so the UI is "locked" (just like when a
drop down list is displayed) and your next click on the app will do
nothing, because this is what would normally close the drop down list.

A couple things to note:
-If the combo box is not empty, it always properly displays the drop
down list
-It is not limited to .NET, I built a C++ app with Visual Studio 6.0
and get the same behavior
-There are rare circumstances where it does work correctly in "Windows
Classic View." Sometimes an empty combobox DOES display the empty drop
down list, but it seems to be very rare. I can not explain why
sometimes it does and sometimes it doesnt. I have not been able to come
up with a scenario where I can consistanly get the empty drop down list
to display in "Windows Classic View", in fact, I have only gotten it to
happen a couple times.

Here are the steps to reproduce (Must be running Windows XP):
-Set your style to "Windows Classic Style" by right-clicking empty
space on your desktop, select Properties, click the Appearance tab and
select the "Windows Classic Style" in the "Windows and buttons" drop
down list
-Open Visual Studio and create a simple Windows App. Drag a ComboBox
onto the Form. Press Ctrl + F5 to build and run the app.
-You *should* see that when you click the arrow in the ComboBox, it
does not display the drop down list.
-Change your style to "Windows XP Style"
-Now when you run the app you will see the drop down list DOES appear.