Ypur Best Bet at this point is to burn the Slayers to Memorex CD-RW media and try.
Because you have the Thomson (spelling??) Drive, you are going to have a hard time getting it to recognize the CD-RW disk you create - It's a "known" issue with these drives.
Other posters have reported having to reboot many many times befre their CD-RW media can be read by this make of drive......
Some posters report NEVER having success with CD-RW disks in these drives. (Bummer)
Your only other option is DVD-R media, and this of corse would require having a DVD Burner, or knowing someone who has one.
Of course there is the option of replacing your Thomson DVD drive with the Samsung model, but I would think you would want to try all other options before going that route. (Your gonna want to buy a new Harddrive - Not a DVD drive!)
I would suggest you do the following:
Get your self some brand new, Memorex CD-RW media. (2)
Copy a Music CD to one of the New CD-RW disks at the slowest possible burn speed.
Place the burned music CD-RW in your Xbox with Xbit DISABLED and see if your Thomson DVD can read it.
If it does, your in luck. Burn the Slayers to your other NEW Memorex CD-RW disk (at slowest possible burn rate) and try to boot the Slayers in your Xbox with the Xbit ENABLED.
It sounds like you've got the Xbit installation done.... You now are having to deal with a Thomson DVD drive that is known to be "dicey" when it comes to booting a burned CD-RW disk.
Do you have access to to NERO software for burning in lieu of the Adaptec EZ CD Creator Software? If so, I would suggest using it as it seems most of the previous posts I have read discourage people from using Adaptec EZ CD Creator.
Keep us posted!