VB6 projects not getting compiled properly from VBP

[kinook]

I haven't heard of anything like that before. Could there maybe be some sort of circular dependency between projects that requires a particular build order for everything to work properly?

You might try putting all the projects in a .VBG file (could generate this using the loop you already have and write the filenames out like Project=filename) and building that from a Make VB6 step instead, letting it update references, and see if that makes any difference.