Lion shows up installed on 10.6

[Ozy]

I installed the GM on a few test laptops prior to release to make sure it works ok with certain apps. Now that release is out and I want to upgrade my main macpro (and pay for it), the app store shows that it is "Installed" already. Obviously its not since I'm on 10.6.

I wonder if it saw that I had it on another laptop associated with my apple ID already and marked it as installed? If so, it's odd that it would mark as installed on my desktop.

Anyone else have this issue?

 

[bradyjfrey]

Figured it out via:
http://twitter.com/#!/demiburaga/status/93823882993217536

They note:

Second, if you're a developer who previously downloaded the "golden master" [GM] of the Lion installer, the Mac App Store will claim Lion is "Installed" on any Snow Leopard Mac—and thus not let you download the official release—if it detects that installer on any connected volume. The solution is either to delete the GM, after compressing it or copying it to a removable drive if you want to keep it handy, or to disconnect the drive on which the GM resides. Third, if you're trying download the Lion installer onto a Mac that's already running Lion (either the GM or the official release), the Mac App Store will claim that Lion is already installed and, again, prevent you from downloading it. Try these tricks: Option+click the Buy App button in the Mac App Store. If that doesn't work, switch to the Mac App Store's main page and then Option+click the Purchases button in the toolbar. If that doesn't work, quit the Mac App Store app and then hold down the Option key while launching the Mac App Store again. One of these three procedures should get rid of the "Installed" status for Lion and let you download it.

 

[bradyjfrey]

...and in my case, deleting the installer off a connected drive worked like a charm.