A custom event is logged incorrectly when you run a 32-bit application in a 64-bit version of Windows Server 2008 or of Windows Vista
On a computer that is running a 64-bit version of Windows Server 2008 or of Windows Vista, you run a 32-bit application that logs a custom event. When you try to view this event in Event Viewer, you notice that the event is logged incorrectly. For example, Event Viewer displays a message that states the following:
The description for Event ID 261 from source LogSample cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.
This problem does not occur on 64-bit versions of Windows Server 2003 or of Windows XP.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB961270.