Once I got things into a buildable state, building with no compatibility works fine in my tests. I've attached a .ZIP file that you can extract and build to test. It first registers the DLL/OCXs, then does a force build without changing compatibility, another with no compatibility, and again without changing compatibility.
Also, FYI: the build rule you had on the second Make VB6 step should be either
[%LASTSTEP_STATUS%<>0] is true
or
%LASTSTEP_STATUS% is not equal to 0
|