Several Monster headphone models using Apple's Remote and Mic technology do not meet Apple's technical specifications. These headphones use conductive flanges, which can result in electrical shorts that cause an iPod or iPhone to pause and play erratically. Customers may not be aware that the issue is caused by the headphones and may believe that the iPod or iPhone is defective instead. There are no known safety concerns and no known risk of damage to the iPod/iPhone or headphones.
Apple has a list of around two dozen models affected by the issue.