Force refresh of designer.cs for Visual Studio 2010 after changing table adapter:

1) Click on the XSD file in the solution explorer
2) Click on the properties tab and check the Custom Tool Property. In
there you should find MSDataSetGenerator. If it's not there, type it
there
3) Once done right click the XSD file and click the menu item Run
Custom Tool.

http://bytes.com/topic/c-sharp/answers/695740-visual-studio-dataset-designer-doesnt-regenerate-designer-cs-code