I have a similar problem with an LG HL-DT-ST BDDVDRW CT21N.
It reads factory disks fine (ie Driver Discs, Manu'r Discs, Game Discs, Films and Music CD's) but will not read any burnt disc. It will not even write discs!
My two desktops (win XP) see the contents no prob, as do other people who have used these discs.
Win Explorer shows the media type & size (ie CD-Rom 702Mb, DVD-R 4.38Gb and DVD+R 4.37Gb) but if I try to open the disc Win7's wizard asks me what I want to burn to disc.
I have hardly used the optical drive (except initial software installs - I tend to use my desktops for writing disks as they are faster) so this problem has only come to light in the last few days. I believe that there has been aproblem since day one.
Also, the only driver listed is CDROM.SYS (win 7 64bit version). My desktops with XP show CDROM.SYS , IMAPI.SYS , REDBOOK.SYS and STORPROP.dll .
Much research indicates that there are no drivers available besides the standard ms driver in win operating systems
I have contacted ASUS (who supplied the notebook with said drive) and am awaiting a reply. I will ring them tomorrow as I believe that the problem is caused by a weak laser strength (or possibly a missing file or driver in system).
ASUS X64JQ (aka N61JQ) Notebook - Purchased 24/07/2010
SATA 640GB 5400 rpm
Mobility Radeon HD5730 1GB GDDR3 dedicated memory
Win 7 Pro 64bit SP1 (up to date)
ASUS Drivers (up to date)