A mate of mine has just bought this player. I need to know if this hack works ok - Press OPEN / CLOSE on the front panel, so that you operate when the tray is open. Use the Remote Control unit to slowly key in 9 , 9 , 9 , 9, 0 in that order. Press OPEN / CLOSE again, the DVD player will return to normal operation. Are there any limitations to it, ie only working a certain number of times etc. Thanks.