With Smartnavigation on, First AutoPostBack Firing twice

[Tracey]

I have a form with many drop down datawindows with autopostback = true.
Smartnavigation seems to work terrifically, except when I enter the first
selection in the first dropdown. It seems to ignore what I selected and
repaints the screen and makes the first dropdown the initial value of "Please
select...". Once I select the value in the first dropdown a 2nd time, all
subsequent dropdowns & Smartnav works perfectly.

..Net Framework 1.1; Visual Studio 2003

Any help would be greatly appreciated.
Thank you,
Tracey