Print Map Activity not accepting Text Fields *

I have a print map workflow that uses the PrintMap activity.  One of the arguments activity is "TextFields" which takes an IDictionary object.  I have tried to put in the fields I want to replaced in the print template but they are not getting sent to the server.  If I grab the request URL from Fiddler it does not include the text field attributes.  However, if I run the "Create a printable map" tool from the "I want to" drop down in my SilverlightViewer app it generates the following:

tf__Title=This%20is%20the%20Title&tf__subtitle=This%20is%20the%20Subtitle&tf__Notes=Here%20are%20the%20notes

If I copy the above parameters and append them to the request URL from my HTML5 site everything works fine.

Is this a known bug in the HTML5 viewer and workflows.

Thanks,