Is there a difference between myDGV.Rows.Count and myDGV.RowCount?
Also both of these seem to be returning Number of rows in the underlying table + 1 e.g they are returning 4 for a single field table such as the following. Are the headers added to the counts?:
myField
x
y
z
RowCount: Gets or sets the number of rows displayed in the DataGridView.
Rows.Count: Returns the number of rows