Syncing KDE PIM / Palm loses birthdays (and possibly other fields)

[twos]

I maintain birthdays of my contacts in the KDE PIM addressbook. When syncing the KDE PIM (kdepim-sync) with my Palm Treo 650 (palm-sync), the birthday information is not transferred to the Palm (although the contacts application on the Palm has a field for birthdays). When editing a contact on the Palm (e.g., changing the telephone number) and syncing again, the contact information is transferred back to KDE PIM. Unfortunately, this resets the birthday info in KDE PIM.