iSync with Mac and Windows

[ho1sch]

Hi,
I have a Nokia 6260 Smartphone that syncs perfect with iSync (Tiger - iCal and Address Book). One month ago I decided to sync the same phone with my office calendar (no contacts, just appointments) with my work PC (Windows XP, via bluetooth using Nokia PC Suite). The sync between the Windows PC and the phone is perfect but when I tried to sync my Mac with the phone, the contacts sync ok but the calendar´s sync fails. iSyn returns an error message that saids that the synchronization could not be completed. And on the phone I recieved a "App. Closed!" error.
Can anyone help me? I really want to have both "calendars" on my phone.

Thank you in advance.
Regards,
Christian