iMac built in CD recorder problem

[John Bussell]

Hi there
We have a recent model iMac (OS 9.1) with built-in CD recorder. I've 
used it to burn music CDs, so know it works OK. The Disc Burner 
software and extension are installed.

The problem arises when trying to burn files. Faithfully following 
Mac Help-Centre, I insert blank CD-R, the drive whirrs into action, 
but the CD does not register. Alternatively, opening Disc Burner 
software yields a window asking me to insert blank media. Upon doing 
so, nothing happens after the CD drive fires up. No suggestion of a 
dialogue box or anywhere to drag files/folders as help centre 
suggests.

Am I missing something really obvious (please forgive me), or is 
there another issue at play?

Thanks very much
John