Device is HTC Tytn ROM vers. running Mobile Active Synch

Zimbra server is 4.5.6

All e-mails synch fully with device over the air except for message's with only a subject and an attached file. If the message has some body text they are openable on the device, if no text they are listed but you cant open them.

The messages look fine in web client and when synched to Outlook using the 4.5.6 mapi connector are openable so the question is what is causing this zombie like behaviour with Zimbra Mobile.