cd-rom not mounting

[linux sohosolutions org]

I was testing different installs for Fedora and when I needed to use the
2nd or 3rd cd - it keeps coming back telling me that it cannot mount the
cd-rom.  At first I thought it might be hardware but another drive has
done the same thing.  I have craeted more than one set of the cd's and did
check the md5sum everytime.  Just wondering if anyone else has encountered
this and if they were able to get around it?

Thanks

Matt