The symptoms that you are describing probably have nothing to do with the drive speed. Optics are typically not a problem at high speeds. The reason that single laser drives have no progressed beyond 56-58x is because they are at the practical mechanical limits of sustainable performance for the spindle motor and the consequences of very high centrifugal force on media. Media with slight defects can disintegrate at these speeds (58x is about 11,600 RPM). The Kenwood uses a multiple laser technology and comparatively low motor spindle speeds.
If there is a problem with high drive speed, it is usually because the throughput from the drive is too fast for the destination drive to handle. If information can't be synchronized properly through a buffer, there might be a problem due to the mismatch.
As has been mentioned, you can slow down the speed of your drive with Nero Drive Speed. However, the symptoms would seem be caused by either some system problem (including the reader itself) or problems reading the media. High speed CD-ROM devices are usually preferable, with few disadvantages except for more noise.