Hi Shamsul,
It is indeed possible to block resizing on the DataRows by setting their MinHeight and MaxHeight properties to be the same value, but I tested this method on the InsertionRow and it didn't remove the issue.
I have created a case to have this issue investigated further by the development team.
In the meantime, you could eliminate the problem by blocking resizing on all of the rows by setting the MinHeight and MaxHeight to the same value on the RowSelector:
<Style TargetType="xcdg:RowSelector">
<Setter Property="MaxHeight" Value="32" />
<Setter Property="MinHeight" Value="32" />
</Style>
Diane Lafontaine
Technical Support / Technical Support Team Lead
Xceed Software Inc.