getcomponents in documentmanager

I've got a vba program going through all the assemblies on our server to create a database.  For the most part it works great, it gets components no problem except for a few hundred files where it cannot getcomponents.  It gets the active config, and I can see everything else but the getcomponents return array is empty.  A good chunk of these files are older but there are some recent ones.  getversion gives me everything from 1950 to 3400.

Any ideas why I can't get components on a few of these parts?

Using sw2007.

SolidworksApi macros