Hello, just purchased MasterQ but I'm not sure which version to install on

1. G5 dual 2.5Ghz with OS 10.3.9
2. PowerbookG4 1.67GHz with OS 10.4.8

The documentation is somewhat unclear. MasterQ v1.5 says in the ReadMe file that it requires UB mac. Does that mean I have to install v1.2.1.1 on both my machines?

Thanks.Ciao