Yes, I've had drives where they are in various stages of failure. In one case it would only fail to recognize audio CDs, but everything else worked fine. It's not a 32-bit vs 64-bit issue, so whomever is floating that idea of full of crap. One of those annoying sorts who likes to feign understanding and just end up perpetuating bad info to people like you.
And there is no drive of better quality than the factory. Quite simply, optical drives fail, and they fail pretty often. Like pretty much anything, sometimes you get a drive that just seems impervious to anything you throw at it, and then sometimes you get drives that fail right out of the gate. Most are somewhere in between. You can buy a replacement from someone else, it doesn't mean it will last any longer than the original factory drive will. Just one more bit of bad info to disabuse you of while I'm at it.
Try Bob's ideas, since they're free or at least lower cost than a new drive, and having a lens cleaning disc around might not be such a bad idea for various other devices. If those don't work, you can replace the drive or have someone replace it. As repairs go, that one's not overly difficult, you just need to be careful about the grounding screw by the speaker assembly. Getting that back in can be a bit of a trick, mostly just because you have to do it blind. Might also be a good idea to disconnect the battery from the MLB, just to be on the safe side. Nothing you're doing should make a bit of difference, but just as a general rule it's a good idea to make sure there's no live current running when working on a unit.