Samsung 352B read problem, Please help!

I have a samsung combo drive (352B), and am recently experiencing DVD read problems. It will act like it is starting to read the disk, then stop, and then it tries again a few more times. It eventually gives up and doesn’t play. On the rare occasion that it does play, it freezes after a couple of seconds. I’ve updated the firmware to t806, cleaned the laser, cleaned the dvd (which was bought in a store, its not copied or anything), but it still does the same thing. This problem happened after I reformatted my main drive, so it used to work just fine…Please help!

Intel P4 2.4C
Abit IC7
Seagate barracuda 40 & 120
Samsung 352B combo
Samsung 512x2 DDR
ATI Radeon 9500