I've also tried disabling and enabling but
the reg key doesn't seem to work...
As explained many times already ( too many times, really ), when there's a problem with activation, the scenery will NOT disappear!! If there's a problem with activation, the scenery will revert to TRIAL mode, running for 5 minutes at time per session, with all its buildings. The Trial doesn't ever expire.
So, don't waste your time thinking that a disappearing scenery has anything to do with the activation/registration.
If the scenery doesn't show up, the problem is entirely different and not related in any way to the activation.
You said you have BOTH the Addon Manager AND the Couatl menus visible. And the Addon Manager reports as "Active", but you haven't said the most important thing: is the scenery reported as "Installed" as well ?
