I have a workflow set up that is working fine for documents that are
checked in through the Web interface. However, when I use Check Out
and Open to modify a document (Word or Excel), when I save and close
the document, it gets stuck in the initial autocontribute step. The
only way to move it forward is to check it out and check it back in.

I did notice that I am getting an error message in the log that
says "System needs login authentication credentials".

Are COAO and Workflow incompatible or am I missing something here?