Download and install the latest codecs. There are several reputable packages to choose from like Shark007's and K-Lite's. Also, before a disk rip you have to make sure that that disk is clean. Ripping a disk with lots of fingerprint smudges and scratches on it at the highest speeds is a bit like speed-reading a Bible with missing pages through those party eye-glasses with the Slinky things on the end. You're going to get missing data, most definitely.