Nullref Exception in Table.OnPaintCell

[schoetbi]

at XPTable.Models.Table.OnPaintCell(PaintEventArgs e, Int32 row, Int32 column, Rectangle cellRect) in S:\xptable\xptable_git\Models\Table.cs:line 7872
at XPTable.Models.Table.OnPaintRow(PaintEventArgs e, Int32 row, Rectangle rowRect) in S:\xptable\xptable_git\Models\Table.cs:line 8606
at XPTable.Models.Table.OnPaintRows(PaintEventArgs e) in S:\xptable\xptable_git\Models\Table.cs:line 8515
at XPTable.Models.Table.OnPaint(PaintEventArgs e) in S:\xptable\xptable_git\Models\Table.cs:line 7682
at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer)
at System.Windows.Forms.Control.WmPaint(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)