Do this manually, not with Software Update.
Re-installing Quicktime 7.7 took care of the problem. It had kept the newer Player application but had reverted to an earlier version of the underlying support framework that works with many applications.
I recently helped where the person had re-installed their operating system. QuickTime 7.5.5 for Leopard - QuickTime 7.7 for Leopard - = New version of Quicktime installed but application reports it needs to have that version installed = Open Application > Utilities > System Profiler and check the Quicktime version in Frameworks vs. Download the latest versions of the best Mac apps at safe and trusted MacUpdate Download, install, or update Apple QuickTime for Mac.
Apple QuickTime 7.7 - For Mac OS X 10.5 Leopard users only.
