InfoPath Dev

First field in my form is a people picker that calls from All Users of our SP server. If I type a partial last name in the text entry box of the picker, and hit check names, InfoPath will pop up a window with a list of name suggestions.

If I embed the form in a SharePoint page, or just call it from the list in SharePoint, when I put in the same partial name and Check Name, I'll get an error window.

If I cancel the error window, the unresolved name is in the box in italics.  Mouse over the name and i'll get a list of name suggestions.

Is this behavior a known deal?

I'm looking at the correlation errors on the SP server, but they don't seem to jive with the problem I'm seeing on screen. 

 And... Just did a little test. Made another list, added a PP field to it, built a simple InfoPath form, and it doesn't act the same way my other one does.

On name check, the simple form doesn't give an error... just shows the username in italics.