Open up System Profiler and click on Disc Burning to see if your DVD drive is recognised. Something similar happened to me a while back when the chipset kext for my board somehow got screwed up and stopped all devices on the ATA bus from communicating with the system (SATA was fine). A quick dropping in of a clean kext and some permission corrections soon resolved the problem.

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MacBook Pro 15" | Mac OS X 10.6 • 2 GHz Intel Core Duo • 2 GB DDR2-667 • ATI Radeon Mobility X1600 128 MB • 100 GB Serial-ATA
Hackintosh | Mac OS X 10.5.6 • 3 GHz AMD Athlon 64 X2 6000+ • MSI K9N AM2 • 2 GB DDR2-667 • NVIDIA GeForce 8800 GT 512 MB • ALC888 Audio • 300 GB Serial-ATA
iPhone 3G • 8 GB