I think it work now. A reinstall with the CD-ROM installer did the trick. I think the culprit was an antivirus warning during first installation (bglman.dll).
You should have simply do what I've said to do, which was not to use the CD, and JUST run the Addon Manager installer again without having to re-download it, because it will get the updated Addon Manager. The antivirus warning was surely related to the old Cloud9 version of the bglman.dll file so, it's not relevant here.
As I've said, the CD is now useless, and can only create problems. The only thing that is important, it's the Serial Number.
Even if this has apparently "fixed" the problem for you, that's not the correct way because now your have activated your Serial with the OLD Cloud9 activation policy, which is only 1 activation per order. So, the next time you change hardware, you'll lose the activation again, and you'll have to revert sending an email for reactivation, to which we'll reply to install the updated Addon Manager so, better do it now.
If you use the new Addon Manager which now accepts older Cloud9 serials using lower case characters as well, it will update your serial to the 6 activations per order we use now, and have less issue in the future with activations.
If you run the Addon Manager installation now, enterin FS9 will ask to confirm your activation (since the Serial is already inserted, it will not ask for it again ) so, if you reply YES, it will move your order from the Cloud9 1 activation per order, to the new 6 activations per order.