I am using the UserProfileService, and am also getting this error. I usually only get the error myself when the form has been open for a while. On a remote test, I saw a user get the error every time they created a new document.
The UserProfileService is a UCDX connection that retrieves data on Form Open. (The first time the form opens, I assign a document author. On subsequent opens, I get the current user's profile, and compare user name against the author to see if I will allow the user to save changes.)
I see posts mentioning load sharing and server farm, but I'm not an admin. Is there something I can do myself for the InfoPath form to fix this problem? (e.g., use a different method to obtain user.) Or is there something I need to ask an Admin to do in Sharepoint Administration so this error doesn't happen?
Thanks for any advice you can give!