I think I've got it!!
I have a BB Bold and am operating OSX 10.8.
After upgrading I lost all calendars on my BB. Today after putzing around I think I managed to resolve it.
The "Desktop Manager" was asking for a writable calendar and I finally figured out how to add one so my BB syncs again.
1) Disconnect your mac from the internet.
2) Calendar > Preferences > Accounts. Disable "iCloud" and any other Accounts.
3) Add a new Calendar from the Pulldown menu. It show's up as an "on my Mac" calendar. Name it something that doesn't match any existiong cals.
4) Go back and "Enable" iCloud and other accounts.
5) Re-connect to the internet.
This worked for me and my BB is synincing again.
Since I decided to upload my contacts to icloud I am no longer able to sync my BB to the contact list that has taken me 7 years to build!
I am using a PC with windows 7 (64bit).
I am very unhappy with apples draconian approach to penetrating the market. What gives. Sure upload my contacts to the cloud but leave them on my computer!!!
Am continuing to search for an answer...
Same problem - ical not syncing to BB torch - now z10 a major issue!?
Says there are "no writeable calendars"
Tried solution above - chose mac mini as location for new calendar...shows option for 1 sec then ical put up error message "Calendar encountered a critical error while saving to the database,and recent changes may be lost. More information may be available in the console."