No, they only use one laser. The laser does have a focusing mechanism that changes for DVDs versus CDs. Chances are that's fouled up.
Before you order one, you want to check what type of connection your existing one uses. Pop the side off your PC and look at the back of the drive. If you have a big 2-3" wide ribbon cable attached to the back of it, you want an IDE/ATA drive. If you have a small >1" cable attached to it, you want an SATA drive.
Chances are you have an IDE drive, unless your computer is pretty new. In that case get this:
link [www.newegg.com]