#1) is your new CD burner an external unit. If so is it firewire or USB? Look on the box it will tell you what kind it is.  

#2) Have you installed the CD burners "drivers"? They may be separate from Toast.

#3) What kind of Mac do you have?

#4) What OS are you running? If 9.1 got to Apple.com and download 9.2 and install it for free.

If the answerers to #1 and #2 are yes then try shutting down your computer, unplugging the CD burner and replugging it in, then restart. Start Toast and see if the name of your CD burner shows up in the Toast window at the bottom.