I try to use your supergrid class.

I have combobox of rowsourcetype 6 in grid.
I open combobox dropdown menu,
move selection bar to last item menu, then back to first item.
After that (without closing dropdown menu) I click in other row.
This causes this other row become active and current row validation
is not executed!

It possible to use row validation in this case? I tried to put
transparent shape
over grid in combobox drowpdown event, but cannot find proper event to
remove shape.