Disappearing Inbox Mail

[gofast321]

Hi everyone. I have an issue... I'm not sure if its a Zentyal problem or an Outlook problem.

Server: Zentyal 4.0.5 fully updated with OpenChange configured and enabled
Client: Windows 7 with Office 2013

I have Outlook set to connect via OpenChange (MAPI) and Outlook is in cache mode. When I open Outlook it defaults to show the inbox however when Outlook first opens it shows no email. If I wait about 30 seconds the email will show up. Then if I wait another 30 seconds they disappear again. Then if I wait another 30 seconds it comes back.  This continues endlessly.  If I try to click on one of the emails (when they are visible) it won't open.  If I click into another folder and then back into the inbox I can then open emails but it still continues to cycle. If I turn off cache mode then nothing will show up in the inbox.

Any suggestions? This issue is driving me crazy!

Thanks.