As demonstrated by Greg B (of xbio) having two or more fileupload components on screen at the same time seems to eat button clicks. Specificially the example shown was that a form had two fileupload components on it, plus a save button. The save button would not respond to the first click with the two fileupload components on the form. Remove a fileupload component and then the button behaves normally - put the removed fileupload component back and the button ignores the first click.