ATA DVD-RAM 6.0Beta4 AMD64 Nforce4 problems

[German Tischler]

Hi,

I am trying to use a DVDR/DVD-RAM drive on Beta4 with an Nforce4 board 
(Asus A8N-E).

Controller:
atapci0: <nVidia nForce4 UDMA133 controller> port 
0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xf000-0xf00f at device 6.0 on pci0

Drive:
acd0: DVDR <HL-DT-ST DVDRAM GSA-4160B/A302> at ata1-master UDMA66

When trying to read a DVD-RAM medium, I see

acd0: FAILURE - READ_BIG HARDWARE ERROR asc=0x08 ascq=0x03 error=4<ABORTED>

The drive is running fine using my ASUS P4PE-X (Intel 845PE) board, at 
least I can mount the media (formatted with UFS, also using Beta4). I 
also have no problems with the drive using other media types (CD,DVD+R).

Could someone please give me a hint ?

thanks
German