A friend has a system configured like mine. He does NOT have a copy of OT7. He has QT 10.2. We tried to download from Apple the correct app. It won't let us instill a copy on his macine.
What version of QT 7 did he download? Only the special v7.6.6 specificially modified for installation and use on latest Mac OS X v10.6, v10.7, and v10.8 systems can be installed. See instruction and link found HERE.