May I suggest you switch to or add bonjour syncing? Bonjour syncs via your own network rather than relying on a cloud solution. Obviously the DEVONthink handbook will guide you, but I did post brief instructions in this thread which was about a similar problem.
You can use both Bonjour and cloud sync if that suits your requirements.
Oh, and I’m sorry @kimaldis that nobody was around to answer your question in 2011. Have you, um, solved the problem? 