Yes, MyMeta 1.2 and 1.3 are different. In the VistaDB plugin project, remove the Reference to MyMeta. (It's probably pointing to the MyGeneration folder.) Add a Reference, and using the "Browse" tab, navigate to the MyMeta assembly found in the MyGeneration13 folder.
I got the entire source from SourceForge, but that may be over-kill for you. There are some VistaDB 3.x specific notes in this FAQ.
David Neal Parsons
www.entityspaces.net