You should start by carefully cleaning the optical disk. Use a cleaning fluid designed for optical media and follow the manufacturer's instructions. Warning: do NOT wipe a DVD or CD with a circular motion! Wipe the disk from the centre to the edge (radially). If this fails to cure the problem, you should clean the optical lenses in both players thoroughly. Dirt on the lens can cause read problems and it does not take very much contamination to create a problem. Factors that contribute to a dirty lens include the amount of airborne dust in the room, smoking residue, dander from pets, and poor DVD care (e.g., inserting dirty disks into the player). You should use a wet / dry cleaning disk, such as the Milty LC2, which can be used with both DVD and CD players (http://www.milty.co.uk/i96c166/Media_Care/LC2_CD/DVD_Lens_Cleaner.htm). This is one of the best cleaners on the market and is quite inexpensive. The cleaning disk has several brushes on the underside. The first brush is dampened with a cleaning solution to wet the lens and the remainder are left dry to wipe the lens. Follow the audio instructions on the disk when you use it. You may need to clean the lenses more than once if they are particularly dirty. (Note that this type of cleaner cannot be used in most automobile CD players, because the narrow slot can damage the brushes. They brushes may also pick up dirt at the entrance to the slot and carry it into the player.) If cleaning the players and the media does not work, then you either have a case of manufacturing tolerances in the players (hardware) and the disk (software) adding up to your detriment or a problem with the transport in the LG player. The former is unfortunate and the latter is repairable.