"You cannot continue. There is nothing to install."
I searched for the problem here and it seems that other people's problems and solutions were based on one particular program they were trying to install, ie OS9.
In my case, I have recently tried to install two different programs, completly unrelated to each other, and I get the same message.
Here are the programs, if that matters:
Palm Treo 650
M-Audio Firewire 410 MIDI Audio interface
Any help would be much appreciated.
G5, Mac OS X (10.4.9)