SelectedIndex change sub on a listbox

[amber]

I'm having trouble debugging my code, and I'm starting to wonder if there
isn't bigger problems here...

I am populating a listbox with the following code:

IsBinding = False
Me.lstAmend.DataSource = _dvRPAmend
IsBinding = True
Me.lstAmend.DisplayMember = "Amend-CP"

I use 'IsBinding' because I have a sub when the SelectedIndex changes on
lstAmend (which is a listbox), and the sub will be called 2X with the above
lines of code, so instead, the sub only runs if IsBinding = True.

I'm having some big problems, and stepping through my code to see what's up.
When I step through the above code, the 2 lines that start with Me.lstAmend
SOMETIMES trigger the selectedIndex change....but not every time.

How is this possible??

Thanks..
Amber