Welcome to LQ!
What are the permissions on /dev/hdc ?
Can you burn CDs as root?
If you can burn CDs as root and not as a user, try adding the write bit to /dev/hdc.
If possible, I would also consider upgrading to a more recent release of Fedora. FC3 is no longer supported, so I would suggest FC5 or 6. This is not the solution to your problem, but it will probably fix it anyway.
I hope this helps