Sharepoint 2010 Workflows and PDF files

I have a sharepoint 2010 document library with several workflows attached. The document library is configured to use the default "document" content type.  The workflows are setup to apply to all document types.  When I upload a MSOffice document the workflows all work as expected.  When I upload a pdf, I can view the properties and it says the document type is "document."   I've done all the ifilter/pdf icon updates to the DOCICON.XML file and the files are indexed correctly and the pdf icon shows up as expected under the "TYPE" column in the view.

When I go to start the workflow on the pdf document, none of the workflows are available to start.  I'm assuming this has something to do with the association of the metadata to the pdf document, but I'm not certain.  Anyone have any explanation, workaround, or third party solution to this problem?