Logic pro 9.1.7 update serial key wrong

Did you buy the full Boxed Logic Studio 2 or the Logic 8 to 9 Upgrade version? You can tell by looking at the box that Logic came in. It tells you if you bought the full version or the upgrade version. Many people have been caught out when buying from places like eBay... buying the cheaper upgrade version instead of the Full version. The upgrade version requires you enter a Logic 8 serial number first to install Logic 9

Failing all that, simply call Apple. They can and will help you resolve this.

If you are certain it was the full version and not the upgrade version (They look identical.. only the small sticker on the box belies any difference) then call Apple... They can check the serial for you.

Also, as an aside... It's easier to update via Software Updates... as that is not the latest version (9.1.8 is..) unless you have good reason not to use 9.1.8?

Additional:

Just to confirm, when you did the original install of Logic 9 ir asked for the serial, which you entered and that serial was accepted... but after you updated to 9.1.7, it asked for the serial again and this time it was rejected?

If that's the case, it sounds like some weird kind of permissions issue.. as Logic shouldn't ask for the serial again once it has been accepted during the initial install process. Have you checked/repaired permissions recently?

Okay. Then the next step is to check and repair your permissions via the Disk Utility....

http://macs.about.com/od/applications/ss/firstaid_3.htm

and then try again to enter your serial...

if that doesn't work.. then I would say you need to call Apple to resolve. Make sure you have your serial for them to check as they will do so....