i have concluded (reluctantly) after reading the subject threads that transferring my palm desktop data to my blackberry desktop, using mac os 10.5.8 requires programs i don't have (outlook) and skills i don't have.
I had the same problem a couple of years ago. I'm not an expert, but I think this is what I did. Open Palm Desktop, Export your Calender (same for Contacts), you'll get a screen select Format, change to csv file and export. I imported my calendar to Apple's iCal and Contacts to Apples Address Book. Then go to BB Desktop, under Information go to Calendar and select the file csv file you imported. The same for Contacts. This my not be 100% correct, but the essence of it is.
Good Luck