The WCF DS Client currently does not support batch updates with entities that have the MediaEntry attriute (IsMediaLinkEntry=true). This makes it impossible to have Streams/Blobs/Documents being part of a transaction by using Context.SaveChanges(SaveChangesOptions.Batch).

It would be nice to have this supported out-of-the-box by the WCF DS Client.

The issue has been discussed here: http://social.msdn.microsoft.com/Forums/en-US/adodotnetdataservices/thread/26387eb6-0798-46a2-9010-8ead84b38144