Index: DataGrid.cs
===================================================================
--- DataGrid.cs (revision 55570)
+++ DataGrid.cs (working copy)
@@ -1283,8 +1283,10 @@
                                ke.Handled = true;
                        }
 
-                       CurrentTableStyle.GridColumnStyles[current_cell.ColumnNumber].OnKeyDown
-                               (ke, current_cell.RowNumber, current_cell.ColumnNumber);
+                       if (CurrentTableStyle.GridColumnStyles.Count > 0) {
+                               CurrentTableStyle.GridColumnStyles[current_cell.ColumnNumber].OnKeyDown
+                                       (ke, current_cell.RowNumber, current_cell.ColumnNumber);
+                       }
                }
 
                protected override void OnKeyPress (KeyPressEventArgs kpe)