Unhappy [Q] Syncing with Exchange Calendar

Anybody else had problems with syncing a Nexus 7 (KitKat) with outlook exchange calendar?

I'm migrating from a Samsung Galaxy S Wi-Fi 5 with Gingerbread and with the setup for a corporate exchange account there was an option to sync the calendar for various previous periods ( 2 weeks to 6 months, including the whole calendar). With KitKat this option is not apparent and syncing appears to only sync up to a month into the past - a backward step compared to Gingerbread. I've managed to add previous events by importing a ics file using Business Calendar Pro. However the syncing stops working having worked for a short while.

Trev