I have a Mashita 842s DVD-RAM superdrive in my Toshiba M400 notebook. I am running XP w/SP3. I don't recall whether or not in the past I've tried to play movie dvds on it using such as WinDVD and Windows Media Player 11. However, recently I've had the need to do so. Unfortunately, although data DVDs (both those I've burned myself and software discs) and audio cds can be read without a problem, movie dvds are not recognized as even being in the drive. The lack of recognition includes Windows Explorer, WinDVD and Windows Media Player. Because the other type of discs work fine, I'm assuming this a software or configuration problem. I've used both Windows and a third party utility and both say the driver(s) are the most recent. I would appreciate any and all assistance in diagnosing and correcting this problem. Thanks.