If value member's column is not included in EditorControl (the grid) SelectedValue property always returns null.

Steps to reproduce:
1. Bind a RMCCB to some data source
2. Enable auto filtering
3. Start the app and enter a value in the text editor of RMCCB
4. Press Tab. You will see that the focus is moved away from the RMCCB but the selection is not changed. Also if you try to open the drop down you will see that it has wrong size. Hitting Escape or Enter instead of Tab produces the correct behavior.

Current row is selected in RadMultiColumnComboBox when the mouse's left button is released.

When auto-filtering is applied to RadMultiColumnComboBox and mouse double click is performed over a row, the selected row is changed to another row.

The RadMultiColumnComboBox throws exceptions if its data source is empty and the AutoSizeDropDownToBestFit property is set to true.

Shift + Tab navigation causes drop down opening of RadMultiColumnComboBox

When RadGridView is unbound and you try to create the columns for the RadMultiColumnComboBox manually, RadGridView throws an exception: "Cannot find column bound to 'field name'"

When you have a GridViewMultiComboBoxColumn in RadGridView, you can't set a custom size to the dropdown easily.