Liteon 812s reading problem at 3GB

vbimport

#1

Dear friends:
plz help me
last week i bought a 812s

my liteon 812s write successfully but verify or read fail most on about 3GB
BUT THE RECORDED DVD IS 100% OK IN OTHER DRIVES
i tried different firmwares (originals and codeguz)
i tried different + & - medias
still same problem on most of 90% writed medias

any soloution ?
Best Regardz
BobZombiE