I have:

```
Tree
  embeds_one :branch

Branch
  embedded_in :tree

b = Branch.create(tree=t).save 

```

which returns true 
and b.id returns a long bsonid

Then I do: 

```
Branch.all.first 

```

which returns nil

How can this be?

ALSO,

I remove the embeds\_one, embedded\_in relationship and it all saves to mongo fine.

What is going on?