cd installs under FC6 fail

[Jack Howarth]

   I am seeing an odd problem under x86_64 FC6. A number
of different programs that I have tried to install from
CD have all failed with the error message of the form...

sh: ./MathInstaller: /bin/sh: bad interpreter: Permission denied


This happens regardless of whether I am in the root account
when I mount the CD or not. I have had to make a tar archive
of the contents and of the CDs, untar these on the hard drive
and run the installers from there. What is causing this problem
under FC6? Thanks in advance for any advice.
                      Jack