DVD Drive won't read DVDs

So my problem is this: My DVD drive simply refuses to read DVDs. CDs work fine and for some reason the DVD with W7 is also read by W7 itself. Any other DVD (both single and dual-layer) are unreadable. Windows simply ejects the tray when I try to open a disc and asks to put in a disc. I tried both retail DVDs and DVDs which I burnt myself, none of them work (except for the W7 install disc).

I also tried reinstalling the driver (twice) and upgrading the firmware from 1.1 to 1.3. I have an Optiarc AD-7173A. I doubt it's the lens seeing as how it's still able to read the Windows disc and it didn't have any problems in XP (can't try that now as W7 is the only OS on my main computer).

So does anyone have any ideas? I'm also thinking about hooking up another drive to my PC to see if that one works and my current drive to another PC but before that I'm wondering whether anyone of you can help me.

CE

Is the drive int, or ext? USb, maybe?

Ken

Internal, it's ATA.

EDIT: Well I hooked it up to another computer running Linux and it's the same thing, reads CDs and bootable DVDs fine but no other DVDs. Guess it's just a hardware malfunction so this is solved. Sort of. Thanks anyway.