We have been testing an application that uses the Infragistics datagrid to display and allow the selection of 1 or more rows for further processing.  The sample included consists of  two public properties (boolean, string) added to the grid as unbounded fields.  The desired business functionality is that whenever the row is selected the checkbox value will toggle to its opposite value.  This works correctly on most test machines, however some machines will experience an application error in the OnPropertyChanged handler indicating that the oldvalue contains an incorrect property value (null).  This only happens when the datatype for the checkbox is set to "sys:Boolean" string or numeric types work as expecteted with the obvious disadvantage of not displaying a checkbox.  The problem has occurred only on machines running Vista 64bit (32 or 64 bit mode) or Home Vista machines.  We have attempted many work arounds and have reduced the issue set to the following sample program.  Changing the datatype on the bound boolean value from "sys:Boolean" to "sys:Int32" or "sys:string" results in the correct behavior, it is only the boolean type that causes the oldvalue property error on the dependecy property.

Attached is a sample program that defines the problem along with the call stack for the failure.  The call stack is consistent on all versions of the operating system where the boolean type fails: