Windows 98 does not detect music CD

I just upgraded a computer from Windows 98 to Second Edition. It had an ISA sound card. The sound was really bad, grainy and drawn out. I installed an Aopen PCI sound card. The sound plays fine now. I don’t know if this is related, but when I put in a music cd, the light on the drive keeps going on and off. The cd does not start playing and does not show an icon in My Computer. When I double-click on it, it says something like ‘Cannot read’ or “please insert a disk’. Data cd’s work fine.