Have you looked at:
http://people.redhat.com/~hhorak/software-collections/mysql55-rhel-5-candidate/
?
If you look there, you will see that there are only .src.rpm and .x86_64.rpm packages. Unfortunately that repository doesn't contain packages which have been built for an i686 target system.
Yes, I had looked at that, but I missed that there was nothing there except for 64 bit systems. I was too wrapped up in trying to get the repository working.
So, my hopes for running a second instance of a different version of mysql on SME has no solution? The repository offered by Software Collections has nothing for me if I don't have a 64 bit system?