Are you putting your material on a core? do you use the centre of the laminator? Are you feeding the material in a straight as possible? Are you monitoring the tension of the vinyl going in? If you answer yes to these questions than your laminator is out of whack. You need to have even tension on either side of the rollers. You can test this with a tension gauge and adjust the screws. Or, call a tech to take care of it for you.