I'm using Chrome - if that matters.
Authorware 7 doesn’t work on OSX after 10.4 or 10.5 It’s a PowerPC(?) app.
You are running the installer from the CD? From a download?
Regardless, if the installer is 'stuffed' ad the Stuffit Expander isn't working on the OS to unpack the archive, then not much you can do about that... Adobe's not going to provide the installer in a different form, and if MaxOS doesn't support Stuffit archives any more...your best bet would be to get Windows running on the Mac under a virtual machine (i.e. Parallels) and use the PC version.