Ray... as I said, I'm not expecting to have this fixed for me.... I'm not sure there are many CS6 users left anymore :) I'd rather you work with the other BETA testers to make sure it works on the newer version of DW.
If CS6 compatibility is important to you. then I will re-open the program and provide a few "recipes" you can look into.
To answer your question... I have only tested using newly created clean HTML 5 pages within a new site space in DW. I am not trying to add anything to existing pages.