Correct Rev File Association?

[Scott Rossi]

A customer of mine is reporting that his Mac system is currently treating
stacks as standalone apps: double-clicking a stack in the Finder launches
the stack as a standalone app without Rev's IDE.  The problem appears to be
a file-association issue.  Looking in the Get Info window for the stack
shows "Standalone (default)" as the default application under "Open with:".
Changing this to any version of Rev and clicking "Change All..." fails to
stick (reverts back to Standalone).

Is there a way to force-update the default app without reinstalling Rev or
resorting to a 3rd party tool?

Thanks & Regards,

Scott Rossi
Creative Director
Tactile Media, Multimedia & Design