Is anyone having success using Zoho Calendar over ActiveSync?  Specifically with the iPhone.  It's never worked quite right for me.  My setup is pretty simple, just my wife and I with separate email addresses on the same Zoho account.  I'll create an event in the iOS calendar app and invite her.  She'll get the Zoho email and click 'Yes' to accept.  I won't get a response saying she accepted but the event will be on her calendar.  She won't initially get the iOS calendar integrated invite where she can accept/decline from there.  About 20 minutes later she'll get the iOS calendar app invite and she can then accept/decline.  When she accepts then the whole event disappears from her calendar.  The behavior is very erratic and buggy it seems.  I have separate Office 365 accounts on these devices and those calendars work fine, all the invitations are tightly integrated with the iOS calendar app, the responses work appropriately and it's just plain stable.

This buggy behavior isn't anything new, I've always had odd calendaring issues when dealing with invites ever since I started using Zoho a couple years ago.  It's just now becoming more of an issue as we try to use this regularly.

Is this feature just not well developed?