I increased the verbosity of the output window during a build. Got that from this link:
This enabled me to see that some of the code wasn't being added to TFS when created in Visual Studio. Specifically the designer and the cbl codebehind for Web Forms generated from Visual Studio in COBOL. You have to add those manually. Perhaps this is a bug in the Visual Studio add ins for Microfocus and Team Foundation Server?
If you add a webform in visual studio, the ASPX is added to TFS, but the designer and codebehind are not.