Tech Support had me uninstall/reinstall 6b. Now Media Manager fails to initialize. I tried reinstalling 6b. It said it sucessfully installed Media Manager. But it still fails to initialize.
I had a somewhat similar problem. It finally turned out that an SQL file in either my Office software or OS was hosed. I discovered this by trying a variety of steps. I finally uninstalled Vegas, then did an Office repair install, and then re-installed Vegas - and that fixed it.