Sony did finally contact me about diagnosing the problem and suggested downloading a program to check the drive. After running http://www.cdspeed2000.com/
I was able to verify that the drive was okay and the problem was a software issue.
Used recovery to convert the registry to several weeks ago, then used Systweak's Advanced System Optimizer. The CD has returned to normal function. Just wish I knew what made it go wonky in the first place.