[PD] MIDI-problem on OS X

Hi all, while trying to make a complex patch work on all major platforms, I encountered a problem on one single G4-Powerbook running Mac OS X 10.3: Pd (0.37.0 extended) starts up, but the terminal prints the error: "Can't start MIDI". Trying to open MIDI settings in Pd returns a canvas creation failure. I simply copied the files of one OS X installation to this powerbook, which worked on several other Macs with G3, G4 and G5 processors. Only this one machine has this problem. MIDI works in other applications, though. Reinstalling Pd from the web didn't help, either. Since I need to use this machine for a presentation with Pd, I have to get MIDI to work on it. Any recommendations what I should do? Greetz, Florian