Body of Accept/Decline Messages blank in non cache mode

Hi all

I have setup some resource mailboxes for some busines cars for sharing.

To inform the users about de law i have put in some additional Response.
The properties "AddAdditionalResponse" and "EnableResponseDetails" are both TRUE

The issue is like the follow:
When Outlook is in CacheMode everything works like a charm.
When Outlook is in NonCacheMode, the Body of the Accept/Decline Message is blank. The 3 lines of the AutoPreviev shows the first lines of the body.

Testet on 2 Exchange Servers with the same result. Testet on Outlook 2010 and Outlook 2013.

Put on CacheMode is not an Option because there is a RDS infrastructure.

Has somone a solution or a workaround?

We are running Exchange ond CU3 and SP1.