Datagridview cell values disappear when using up and down arrow keys to scroll

Hi,

      I am using an unbound datagridview . It has allowusertoaddrows = true . After entering about 20-30 rows if i scroll up fast using the up arrow key the cell values disappear until i stop scrolling. The same happens while scrolling down using the down arrow key. This behavior is unacceptable to my customer.

Please help

Regards

Sanjish