This one had me stumped for days. Infopath form with drop down field populated by internal values in the drop-down.
I needed to add one option, which I did and uploaded the form. I could see the version number updating on the form (I display that as a field) but the drop-down wouldn’t change!
Turns out I had a read-only and updatable versions of the form. The read-only version is displayed after the form has been submitted. I was editing the read-only version not the editable one that gets filled in. Doh!