Error Converting PDF to TIFF

I'm trying to use the toImage service in Common/Convert PDF and I'm getting errors saying my input PDF is not flattened. So, I added a transformPDF step before my toImage. When I write the output from the transformPDF step to the file system and open it with reader it seems to be flattened (i.e. no fields everything is static). However, when I take that output and run it through the toImage service I still get this exception:

com.adobe.livecycle.convertpdfservice.exception.ConvertPdfException: Input Document is not a flattened PDF Document

Anybody have any ideas how to get this conversion to work?

Thanks,
Bryan