NEC 3500A DL DVD reading problems

Hi there,
Yesterday I tried to rip 2 DL DVD Movies disks, which are region free disks,
exactly at the middle of ripping process ripping failed( using DVD Decryptor). Also I noted that even simple copying failed at 51%. Looks like that the second layer is not read . Also one disk ca be ripped using NERO, but second failed again at ~51%. May be I need to update some Drivers from MS site.
PS. this disk was successfully read on normal DVD-ROM. I have installed WinXP with no service packs