So I have a folder name ending in .theme and I can't change it to anything else. (It's part of a Plone installation with XDV.) This makes OS X think it's an iDVD theme, not a folder. To browse its contents, I have to right-click "Show Package Contents". How do I make Finder treat it like a normal folder? (I don't use iDVD.)
Uninstall iDVD (if possible), or delete the iDVD application bundle.
Then either rebuild the launch services database by entering the following in Terminal:
or restart your machine.