I just saw this on an InfoPath site:
Before you publish your form template to a list of e-mail message recipients, you need to do the following:
Verify that your form template does not have any query data connections. You cannot publish a form template to a list of e-mail message recipients if the form template contains a query data connection. If you need to display data from an external data source, store the data from the external data source in a resource file. Then you can include this resource file with the form template.
- http://office.microsoft.com/en-us/infopath/HP100997611033.aspx
We have some web service queries that load some drop downs with user contextual information from a web service on load.
Could this be the reason for the certificate error? It seems like it should be throwing a different error message if that was the case.