I've got several forms that read from a secondary data connection using a SQL http endpoint webservice. The secondary connection works fine using the IP client but becomes an issue when published to MOSS 2007 and rendered as a web based form. I've converted the secondary connection to a UDC and uploaded/approved in the MOSS data connection library. I confirmed that the IP client can reference the UDC properly and read from the secondary.
Played around with Central Admin settings enabling/disabling form proxy options to no avail.
Error message is the generic Warning - "some rules were not applied" - "An error occurred accessing a data source".
I've gone throught the steps found here and still can't figure it out.
http://blogs.msdn.com/b/infopath/archive/2006/10/02/data-connections-in-browser-forms.aspx