OK, I assume you changed the boot order in the BIOS to actually boot off the CD, or pressed ESC at boot to manually select the CD as the boot device.
In a situation like this, and certainly before RMAing it, I'd be tempted to remove the DVD recorder itself, clean the contacts with some acetone or 99% alcohol, and re-seat it back in the notebook. You'll have to go into the notebook from the bottom and unscrew one particular screw to release the player. Take 'er out, clean, and reseat.
See step 5 of this guide:
http://nekaka.com/files/get/T16uV7IeCt/asus-g74-disassembly-guide.pdfUnless someone else on here has other trix to try?
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G74SX-CST1-CBIL, i7 2630QM 2GHz
32GB DDR3 RAM @1333MHz
GTX560M 3GB DDR5 (192 bit)
17.3" LED 1920x1080
Sentelic TP, BIOS 203
Debian Linux Wheezy (Testing) Kernel 3.2, NVIDIA 295.40