After about 8 hours of messing around with GroupCal, I can say one thing is certain, make sure that you have a good backup of your Exchange calendar and your iCal calendar.After an email to technical support, I found out that I could manage my tasks the way that I wanted to – categories in Exchange map to calendars in iCal. Bravo for that feature!So, initially, when I had Exchange syncing with just one iCal calendar, everything worked fine. Then when I tried to change the setup so that my tasks went to the various iCal calendars, things began to get pretty muddled. Some appointments would duplicate themselves multiple times on my Exchange calendar. Some appointments on either calendar wouldn’t show up on the other Calendar. I tried setting the GroupCal categories. GroupCal uses some custom categories to manage the synchronization. All to no avail.The calendars became unusable. I eventually had to have my calendar and tasks on Exchange restored from a recent backup.Now, I haven’t contacted Snerdware support yet. So this may be still be a viable solution.