Still can’t get the iTunes on my computer to burn an audio disc!

Let’s see. I’ve gone to the new playlist I made, which is titled “Burn this to disc”. When I click it, the side window opens and shows the songs I’ve dragged in there. I make sure each song’s “checkbox” is checked. Then I click the “Burn Disc” wheel on the top right. It asks for a blank disc. I put in my CompUSA 16x 700 Megabyte CD-Recordable blank disc. iTunes says “Checking Media”. After it flashes that a few times, it says “Click Burn Disc to start…13 songs, 55:53 total time.” I click the flashing Burn Disc wheel. It says “Initializing Burn Disc” and the song titles flash by. Then it says “Writing” and lists the first song, and the Burn Disc starts wheel starts spinning. After about 15 seconds, it says “Canceling Burn Disc, this may take a minute.” Then it spits out the disc and I get the error message “The attempt to burn a disc failed. The device failed to respond properly, unable to recover or retry.”

Spec’s:
Machine Model: iMac G5
CPU Type: PowerPC G5 (3.0)
Number Of CPUs: 1
CPU Speed: 1.8 GHz
L2 Cache (per CPU): 512 KB
Memory: 512 MB
OS X (10.3.5)
iTunes v 4.7
CD Burner; Matshita DVD-R UJ-825
Quicktime 6.5.2

More details: Out of the 13 songs, when I go to get info, I see that 9 are Mpeg, and 4 are AAC. Is that a bad thing, and how do I fix it, if it is?

Are the CompUSA discs the problem?

I checked the songs in their folders, all are listed as Read & Write in Permissions.
I’ve done the iTunes software update from Mac.

I’m gonna hate having to lose my computer to take it into the shop to figure this out!!! Help! 🙂