Futon, create New Document and change _id, clicking Save Document will save but sends you to wrong doc

Steps to reproduce:

• Open a database in Futon
• Click "New Document"
• Switch to Source view
• Change the generated _id to anything else
• Click "Save Document"

The document is saved under the given _id, but when the page reloads it tries to access a document under the original generated _id. You may also get a dialog that says "missing".

If you create a document and specify the _id, then it should load that _id as that is what it saved.