I have a HK 520 and it freezes sometimes when playing a dvd. It never does this when playing CD's, the regular tv stations or VHS tapes. It is on a rack with shelves and no sides, there is only a bit more than 1" to the next shelf above. Will taking the shelf above and giving it more ventilation fix this glitch? The movie was the Bourne Identity, not a very demanding special effects movie or exceptional bass passages. Also was playing only about -25 db. Does HK have any fixes for this. Is it more than heat causing this problem. The disk was pretty new only came out last week.