No agents for the queued builds

We have a setup by which we use a combination of snapshot depencencies to pass along build numbers as well as changelist and other informations from one configurations to the another.  Our set is the following

A has dependency on B and C
Both B and C have their snapshod dependency set as following
D is set  to run on the same agent
E is set to always run.

A can run on any agent
B is a Windows agent and C is a Mac agent
B and C are dependent on D and E



When we launch the A, B, C, D and E are added to the queue.  Only E completes it work.  Other builds, A, B, C and D stay in the queue with the following message,

"No agents" and the reason is "Cannot estimate this build Build dependencies have not been built yet"

The reason I beleive is build D which is set to run on the same agent has only one build in queue and it is also pointing on A which is not dependent on it.  If I remove D from the dependency list, then all other builds start, but will fail since they need files from build D.

So what am I doing wrong here?

Can we have two snapshot dependencies?
One thing to note here, D can run on multiple platforms.