Moved Post - SQL UM and Infopath forms

I have created a local website where I have published an infopath form. I used the wizard to create the process and during, I selected the "Enable TaskPane Submit Button only for Destination User" check box. When I go to the form and click submit I get the following popup:
"An exception has occured. Unable to connect to the K2.Net server. Authentication with server failed". In the help docs, it says the following:

"The InfoPath form will disable/enable the Submit button based on the current logged on user."

I am using SQL UM.. ANy ideas as to what I am doing wrong? Do I need to change the connection string in the infopath form and if so, what to?

Thanks