[.Net] The type 'Microsoft.CompactFramework.Design.UnsafeUserControl' has no property named 'XXX'

I create a user control and it use another user control.
It met some problem when I view it's design and the saw the message,
The type 'Microsoft.CompactFramework.Design.UnsafeUserControl' has no property named 'XXX'

I follow the step as below to work around it,
1. In the Solution Explorer of VS2005, right click on the class file and 
select "View Class Diagram" (This will open the Class Diagram file). 

2. Select the class and open the Properties window. 

3. In the "Custom Attributes" field, click the browse button. A dialog 
will be displayed and enter the following: DesktopCompatible(true) 




Reference:
http://forum.soft32.com/pda/VS2005-Design-UnsafeUserControl-Error-ftopict60562.html