(ES3) Adding Invisible Signature field?

[C_Batt]

I understand that Signature Service can't Add Invisible Signature Field to a Dynamic XFA PDF, so I'm trying the following:

1. Forms Service's renderPDFForm operation to Merge Form and Data; and then
2. Output Service's transformPDF operation to Flatten PDF.

However I still get the error: ALC-DSS-300-007 Addition of Signature Fields is not supported for Dynamic XFA PDFs

This seems to indicate that previous steps I took do not in fact transform a Dynamic XFA PDF to Static PDF.

Is there are way to transform a Dynamic XFA PDF to a Static PDF so that I can add an invisible signature field that can be used by the Signature Service's Certify PDF operation?

(I feel like I must be overlooking something simple, and my google-fu is failing me.)

[C_Batt]

Bit ashamed of this one.  Was simply doing something wrong in the FormsService renderPDFForm operation to merge the form with data.

For anyone in the future that is experiencing the same problem, in the FormsService renderPDFForm operation of the process, view All options in the property sheet, and under:

• PDF Options, check "Generate appearances on server"
• Render Options, set "Render at Client" to "No"
• Additional Options, set "Form Model Processing" to "Server Side"

Explanation here: http://blogs.adobe.com/steampowered/tag/livecycle-output