I purchased the Lite-On 20X LH20A1H....
So did I!
Maybe I got a bad one?
'cause mine doesn't clear the drive door very well in my 2008 MacPro, I had to tinker with it just to get it to open, I remember someone else on this forum mentioning the same problem. I didn't have that problem when it was in the FW800 PowerMac G4.
The problem with it in my FW800, and still with the MacPro, is that it refuses to recognize a good number of my Burnt discs. I also fails to recognize my batch of blank Verbatim DVD+R DL discs. This is even after the latest Firmware (LL0D) update. It does Lightscribe well though, which is what I mainly used it for in my G4. I used my NEC 3550A external for burning. After the Drive door problem, I sent the Lite-On to my old pc, and installed the Samsung SH-S182M (from the old PC) in my MacPro. The Samsung (TSSTcorp SH-S182M) does Lightscribe too, and recognizes the discs that the Lite-On doesn't.
I would recommend any drive that's on the LaCieProfile_Feb2008 list, except the Lite-On 20X LH20A1H drive;
http://www.lacie.com/support/drivers/driver.htm?id=10055
TSSTcorp SH-S203N
TSSTcorp SH-S182M
TSSTcorp TS-L632M
TSSTcorp TS-L632L
TSSTcorp SH-S162L
NEC ND-3550A
TSSTcorp SH-W162L
NEC ND-3540A
NEC ND-3520AW
IDE-DVD DVDRW8651
NEC ND-3520A
Lite-On SOHR-5238S
NEC ND-3500AG
NEC ND-2510A
Lite-On SOHW-812S
Matsushita (Panasonic) SW-9572
Some of these are NOT Lightscribe capable. You need the LaCieProfile_Feb2008 to give your drive 'Vendor Supported' status in Leopard's burn support, else it will show up as 'Generic Support'. PatchBurn doesn't work with Leopard. I see a lot of Samsung (TSSTcorp) drives on that list, I'd go for the TSSTcorp SH-S203N with the Book type patch,
http://club.cdfreaks.com/f105/patch-utility-samsung-mtk-based-dvd-writers-v2-3-1 -new-242508/
😉