Hello,
I am currently using the GetUserProfileByName data connection inside my InfoPath form and it works well. The only problem is about 50% of the time I get an error saying that "An error occured querying a data source". This happens when I first open the form and then occasionally when I populate the people pickers inside the form. Nothing happens to my form when I get this error upon loading it, but if the error occurs populating the people picker it will display their user ID instead of their emails (I used the instructions in this blog http://alecpojidaev.wordpress.com/2008/12/16/infopath-codeless-programming-walkthrough/). The form I created was made possible mainly by reading items in this forum so if anyone could help me with this final issue that would be great.