Using Alcohol no matter how pure (99% isopropyl is the best you can buy, BTW... there is always a little water), is NOT good for the AR (Anti-Reflective) coatings on photographic lenses.
Look at your manuals... Carl Zeiss, Leica, Hasselblad, Nikon, Canon warn you to NOT use alcohol to clean their lenses. Alcohol can and will remove the precious AR coatings on your lenses. And these are glass lenses your CD lens is made of plastic. Think of CD lenses as mini photographic lenses... in fact they are. The optical purity of these lenses is extremely high.
Etch / fog the lens with alcohol or remove the AR coating and you might as well buy a new CD drive. They will read and/or write at an unreliable rate and create lots of beer coasters. But if that is what you want... by all means, go for it.
What to use...
Start with blowing some compressed air ACROSS the lens surface. It's the best cure for a misreading CD-Rom, CDR, CDRW drive. This solution will cure MOST CD read problems. NOTE: you always want to blow compressed air ACROSS but never directly into the lens as you could force some grit into the lens mechanism itself.
A CLEAN photographic lens brush can also be used to carefully brush away any offending material. The best type are the ones with a small air bellows so you can blow some air across the lens and then brush.
If that is not enough de-ionized water is, believe it or not, an excellent lens cleaner. So is Kodak lens cleaner (de-ionized water with stabilizers and optical brighteners added). Use a lens tissue (Kodak is good) or a PHOTOGRAPHIC quality lens swab to clean. Q-tips that are normally bought in stores are also bad. They are not of sufficient quality to clean lenses. Photographic swab tip's material is of much higher quality. BIG warning... this MUST be done VERY carefully... else you will move the lens or lens carrier when cleaning and will misalign your CD-Rom lens and mess up the drive. Beer coasters anyone?!
Lastly, be careful about opening the CD-Rom case during the warranty period. Most manufactures will void your warranty if you open it up. If the drive gives you CD read problems during the warranty period, have it cleaned by an authorized dealer. Besides, it's usually free!