Hope you don't mind me borrowing your thread.
Similar and related problem.  I've been at this most of 2 years now and as such have a good grasp of the librarys and structure but have run into something that's both frustrating and puzzling.  I have DAZ/Studio 3 accessing the Poser 7/runtime without any problems but it doesn't seem to want to access the Poser 7/downloads library.  I have it now just accessing Poser 7/runtime and the DAZ content but can't get the downloads library to show up.
And you thought that it was only newbies that got confused over this! ;)