The following are some of the differences between versions 1.0 and 1.1 of the framework that relate to Windows forms:
Calling Form.Close in the Load event of a modal form now closes the form.
The Validating event no longer fires twice when closing a form.
Adding a nonserializable object to the Clipboard now generates an exception.
The ListView object no longer fires the MouseUp event when the ListItem is dragged.
The TreeView object raises the MouseUp event correctly when the mouse button is released.
The TrackBar control now raises ValueChangedEvents when the value is changed via the mouse scroll wheel.
Setting the DataSource property of a ListBox or ComboBox to Null will now clear the contents of the control.
A data-bound ComboBox with its DropDownStyle property set to DropDownList now finds items by programmatically setting the Text property.
When a form is closed, the Validating event does not fire for the control that has focus if that control is in a UserControl.