I just started using Zoho calendar.  I've successfully synced it with two other calendars (from Google and Yahoo).  All events are visible on the web version of Zoho Calendar.  But duplicates of each item imported from my Google calendar appear when I access my Zoho calenday through my mobile device at mobile.zoho.com.  How can I stop these events from appearing in duplicate?  (Note: the events imported from my Yahoo calendar appear only once, not in duplicate).

Thank you.