*KNOPPIX n00b warning*

I recently installed Knoppix 3.9 on my HDD, and everything ran smoothly with no problems at all. It boots correctly, programs run correctly, and...pretty much it was a totally successful installation. EXCEPT...when I put a CD ROM into the drive and click the drive icon, a message comes up and tells me that the drive is not accessable and doesn't exist. Is there something I have to configure? Because when I run it from the LiveCD the drives work fine. I read about mount points, but I'm not sure if they're what I need to get the ROM drive to work correctly. Anyone got any pointers?

Thanks.