DataGridView RowCount set is slow

[AndrusM]

I have DataGridView in virtual mode containing 3500 rows. In code below, assigning to RowCount value to 3500 takes 8 seconds. CPU usage goes high at this time. Stepping by F11 into user code shows few celltemplate property getters and combobox/datecombo constructor calls without database access which does not take a lot of time. Debug output (below) shows lot of messages Stepping over non-user code. Running in release mode from Windows this line speed is same (slow). How to speed up grid creation ? Using C# Express 2008 3.5 SP1 in Vista.

class Grid : System.Windows.Forms.DataGridView {

    internal void SetDataRetriever(DataRetriever<TEntity> dataRetriever)
    { ......
        SuspendLayout();
        Enabled  = false;
        int cnt = DataRetriever.RowCount + (ReadOnly ? 0 : 1);
        // next line takes 8 seconds:
        RowCount = cnt;
        Enabled = true;
        ResumeLayout();
    }

    protected override void

OnCellValueNeeded(DataGridViewCellValueEventArgs e)
{
if (!Enabled)
return;
...
}

    protected override void OnRowEnter(DataGridViewCellEventArgs e)
    {
        if (!Enabled)
            return;
        ...
     }

}

Debug output window contains: Step into: Stepping over non-user code 'System.Windows.Forms.DataGridView.RowCount.set' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewColumn.CellTemplate.get' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridView.CompleteCellsCollection' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewColumn.CellTemplate.get' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridView.CompleteCellsCollection' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewTextBoxCell.DataGridViewTextBoxCell' Step into: Stepping over non-user code 'System.Windows.Forms.PropertyStore.GetObject' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewCell.Style.get' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewTextBoxCell.Clone' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridView.CompleteCellsCollection' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridViewColumn.CellTemplate.get' Step into: Stepping over non-user code 'System.Windows.Forms.DataGridView.CompleteCellsCollection'