Could you also take a look on this situation ?:
There is a grid with GroupSummaryView and GridRowEditing. Suppose sumarry is based on value edited with ComboBox. When in edit mode you change value of this combo the selected value is applied to all rows in this group. The same situation in IE and FF browsers.
@Jarema Please do not report multiple bugs in a thread. If you think there is a bug with grouping and editing please submit a new thread and include the details of the bug including a test case. Thanks.