This is sounding suspiciously like there is some error in the way they wrote their html or javascript, meaning that messages are accidentally getting displayed that should not be. I have that happen all the time at Ancestry.com, since my browser is out of date, rather than there being a problem with the way the page is written. But I would guess the same thing can happen if there are technical difficulties at the website itself. Error messages get triggered and displayed which should not be, and can really confound the visitor. Yes, writing them is a good idea.