I had the same thing when I recently bought the 20m&topo and it just wouldn't install properly. The solution was to do a complete reinstall of FS altogether and start with a clean slate. Well needless to say it all went flawlessly. I now consider FS9 to be a 5 disc sim as standard and then add my other addons.
I found with the problem of a partial install of RBE I was chasing it or bits of it or other addons that had gone silly on me all over the place and by far the best and easiest was to start fresh.
I'm certainly not 'going above the boss' just saying what worked for me. Maybe Christian might like to comment on what I did.