Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Tips on importing Calendars From Palm Desktop 4.0 or later to your iCal
Note: This guide works for iCal 2.x, iCal 3.x, iCal 1.x and Palm Desktop 4.
1. Launch Palm Desktop 4.0 or the later versions
2. Go to the Export option and select it. Its under the File menu.
3. Select Save As field and enter the name of the file you want.
4. A pop-up menu will come up. Select ‘Date Book’
5. Once done, move to Items pop-up menu and choose ‘All Date Book Items’
6. Move to the Format menu and select ‘vCal’
7. Select ‘Export’ from the Menu now.
Once done, you need to import these in iCal. For this:
8. Open iCal.
9. Move to the Calendar list and select the calendar that you want to import.
10. Click on Import. This lies in the File menu.
11. Now it is the time to import the vCal file that you exported from Palm Desktop 4.0. For this select the file and import it.
As a short cut, you can directly drag the ‘vCal’ file on to the calendar you opened. Once vCal is opened, the list is added to the calendar you opened in vCal.