I turned off Wireless Sync for all (2 - Desktop and Device Default) of my calendars (wireless sync for Device Default was off already). When I go into Desktop Manager, Backup/Restore, Advanced, it still shows all the choices that start with Calendar as greyed out. When I exit DM and check the Calendar options on my phone, Wireless Sync has been turned back on for Desktop.
I'm guessing this is because I am activated on a BES, maybe?
Regardless, I still don't see any way to delete all the entries on my Device Default calendar.
Verizon 8130 (on the bench, now
Verizon 9530 (replaced by VZW 4 times, then with a 9550)