For those that are interested, I've recently purchased a large lot of Sony DVD burners that are compatible with the Liteon LVW-5045 DVD Recorder with 160gb Hard Drive. I am modifying them to fit the 5045 right out of the box. They are being offered on ebay for 59.99 including shipping (while they last).
These burners are Sony Optiarc AD-7190A's which are really rebadged Sony DRU-190A's. All you need to install is one of these is the original 4 screws that mount the original burner. You will also need to bend back the metal guide clips inside the front panel in order for the PC burner to fit.
It comes with illustrated instructions and should about 15 minutes to install. Here's the link: