Selection in a ComboBoxEditor change the row selec

Question

Here is a good problem :

I've got an AdvancedDatagrid with Combobox as ItemEditor (until there, no problems ...). This ComboBoxEditor get this behavior : selection = close editor

BUT

when I click on a value in the ComboBox, it selecte it and close as wished, but the click also put the selection in the row of the datagrid below, and then open the editor of this row.

This comportment appear only with Internet Explorer (8 & 9)

Any idea why it's like this with IE, and more important, how to workaround this ?

Thanks a lot