We have added some new enhancements to Exchange and Office365 support, including Calendar and Contact Sync.
For these to work well, you may need to remove and re-add your account as Exchange ActiveSync.
To remove your account, please go to Settings | Account Settings | [select the account you would like to remove] | Remove Account.
When re-adding the account as ActiveSync please select Add Account | Manual Setup | Exchange | ensure the ActiveSync checkbox is enabled and continue to add your account.
