It may just be that the laser on the drive is dirty. Get a CD-ROM Drive cleaning kit, and run it through, and it might solve your problem. Also blowing some compressed air into the drive may help as well by moving some of the dust away.
If it doesn't, then you may have a bigger issue, such as the laser being misaligned. If your drive is still under warranty, then I suggest you RMA it if it wasn't your fault. I had this problem once with my Lite-On drive, and I managed to fix it,
but it basically was a total fluke. At least the drive works perfectly now. Note, not only do I think it was a fluke, but it may not work with your Sony drive either.
What I did was open up the drive carefully, and then, once inside, I slid the laser mechanism (without touching the laser), all the way to the back of the drive carefully, and it should just slide gently and easily. Then reassemble the drive, not changing anything other than this. I guess doing this realigned the drive, but I only did it because I already voided the warranty trying to stealth the drive (note, make sure you don't open up the drive with a CD still inside, guess how I caused my problem.
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As I said, I don't know why this worked, and if anyone else has a better solution, feel free to correct me.