Since I synced Contactizer Pro with iCal, a new calendar called "Contactizer Pro" appeared and most of my iCal events are duplicated. What happened?
As described in the first question "Does Contactizer Pro sync with iCal?", Contactizer Pro can be synced with iCal but was not designed with this goal in mind. Syncing with devices, via iSync, is our priority, everything has been thought this way, and not to ease iCal parallel usage.
Contactizer Pro, when syncing with iCal, creates a "Contactizer Pro" calendar in iCal. Only this calendar is synced with Contactizer Pro, the other ones are not. iCal data may be duplicated in "Contactizer Pro" calendar only because you first imported iCal data in Contactizer Pro then synced. When you imported iCal data, they were copied in Contactizer Pro. Then, the sync did push them in iCal's "Contactizer Pro" calendar without knowing they could be duplicate. In iCal, just uncheck "Contactizer Pro" calendar and all those duplicates, although being still there, will be hidden from iCal calendar view.
Do not forget that, since iCal's "Contactizer Pro" calendar is the only one synced with Contactizer, if you uncheck this calendar, you'll not see synced modifications in iCal!
Contactizer Pro, when syncing with iCal, creates a "Contactizer Pro" calendar in iCal. Only this calendar is synced with Contactizer Pro, the other ones are not. iCal data may be duplicated in "Contactizer Pro" calendar only because you first imported iCal data in Contactizer Pro then synced. When you imported iCal data, they were copied in Contactizer Pro. Then, the sync did push them in iCal's "Contactizer Pro" calendar without knowing they could be duplicate. In iCal, just uncheck "Contactizer Pro" calendar and all those duplicates, although being still there, will be hidden from iCal calendar view.
Do not forget that, since iCal's "Contactizer Pro" calendar is the only one synced with Contactizer, if you uncheck this calendar, you'll not see synced modifications in iCal!