I can install WireFusion 4.1 on OS X 10.3.9. Whats wrong?
There is a Mac OS X bug that affects how certain programs are installed (WireFusion included) on OS X 10.3.9 systems with the QuickTime 7.0.4 upgrade. This appears to only affects systems running 10.3.9, and not 10.4. The current workaround is to revert to QuickTime 7.0.1, through a reinstaller available from Apple on the Support/Downloads page.