Hi I have a problem I cannot understand.

I have created a form which has a datagridview.
When I start the application I fill in the datagridview by doing the following

Create a datatable and add its rows.
and then fill in the datagridview by:

dataGridViewSpelarUtv.DataSource = dt;

Then I change the height of the rows by:
for (int i = 0; i < dataGridViewSpelarUtv.Rows.Count; ++i)
{
dataGridViewSpelarUtv.Rows[i].Height = 18;
}

That's it!

But the problem is that the height doesn't change? the new values are added in the datagridview but the height is more than 18.
If I now press a button in the application that has this datagridview and call the same function that updates the datagridview the height is changed? Can someone please tell me why?