Hi Joerg,

Currently the XamComboEditor already brings the selected item into view when you open the drop down.  The editor tries to bring it to the top of the drop down.  If you need it to move to the center of the drop down, you can try the code provided here.  This stackoverflow post mainly refers to the ListView control but the code provided in the first answer is designed to work with an ItemsControl which the ComboBox is.  You can access the combobox through the XamComboEditor via the ComboBox property. (i.e. xamComboEditor1.ComboBox).

If you use this code inside of the DropDownOpened event for the XamComboEditor, you will have to use it inside a Dispatcher.  If you don't, any scrolling you try to do will just get overridden by the XamComboEditor.