If the CD drive that isn't working properly is in fact the AOpen, I wouldn't be surprised. We got a batch of them here where I work and they have been failing left and right. Stuff like the belts breaking as well as your problem, the drive just starts failing to recognize it has a CD inside. If this is the drive in question, I highly recommend a better drive. Having had to deal with this problem here, I will probably NEVER buy an AOpen optical drive for my own rig.

Hope this is of some help