OData JSON missing "innererror" object

Hi,

Does anyone know why the $format=json OData responses from Gateway omit the "innererror" object when messages are returned?  I am returning 4 messages from Gateway and all four can be seen in the atom+xml response, along with the lead message, but with JSON I only get the lead message.

I'm running GW 2 SP04.  Is this fixed in a later support package?

Many thanks,

Andrew