Just to finish my part of the discussion, I called customer support. They were unable to resolve the issue, but I was happy with the service. They looked very deeply into the records, then screen shared into my computer and tried several different things. They were able to look at the error reports in their own database, which is info that you can't get on your own.
My personal guess at the issue: after I successfully sent the federal taxes, I should have manually saved and closed turbotax.
