Even before it is inflating its wings, the butterfly is putting together its proboscis. If it has not happened by the time the wings are inflated, it is not going to happen. It can also be a genetic problem--defect.http://www.youtube.com/watch?v=l67SLCOYoHA&NR=1
Put this video on large and you can see the palpi moving up and down, while the butterfly fixes its proboscis. This is going on before the wings are inflated.