When i am creating the custom combo box control in WPF, i have faced one issue regarding SelectedIndex on testing. Then i have searched more and found this is the known issue of ComboBox. Please find it from below link:
http://social.msdn.microsoft.com/Forums/vstudio/en-US/af13c8b3-7e0e-43c0-87a7-53f5a5158512/problem-with-the-selectedindex-in-wpf-custom-combo?forum=wpf
http://social.msdn.microsoft.com/Forums/vstudio/en-US/af13c8b3-7e0e-43c0-87a7-53f5a5158512/problem-with-the-selectedindex-in-wpf-custom-combo?forum=wpf
