I followed the same approach I’ve always used in the dynamic master project.
At this point, I don’t have a reference to compare against, so I’m unable to explain what might have been done differently.
If you could send me your sample dynamic master project along with the sub-projects via email, I’ll take a look and let you know what’s different.
Please feel free to email me if you'd like to discuss the differences and how we can resolve them. ineejuatyahoodotcom