We are currently on Exchange 2013 CU3 with Online Archiving Enabled for the user
Default policy is set to move all the items in mailbox which are older than 30 days to online archive mailbox.
Calendar and Tasks Items are also getting archived alongwith other Outlook items from Inbox,Deleted Items etc
Followed Technet website and created RPT for Calendar and Tasks with retention disabled
Still DPT takes precedence and move all the items under Calendar and Task to Online Archive Mailbox