After upgrading NetBSD 1.5.2 to the new release 1.6, I run into
Ultra-DMA trouble when booting up.

The motherboard is a Gigabyte GA-7VTXH+ (utilizing the KT266A chipset),
using a VIA VT8233A controller, which is supposed to be supported by
NetBSD 1.6.

The IDE cables should be ok. I twiddled with the BIOS settings, even
updated the BIOS, at no effect.

Both drives are affected, wd0 is master on primary, wd1 is master on
secondary IDE port.

I really hope someone can help me out.

Here is the relevant dmesg output:
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pcib0: VIA Technologies VT8233A PCI-ISA Bridge (rev. 0x00)
pciide0 at pci0 dev 17 function 1: VIA Technologies VT8233A ATA133 controller
pciide0: bus-master DMA support present
pciide0: primary channel configured to compatibility mode
atapibus0 at pciide0 channel 0: 2 targets
cd0 at atapibus0 drive 1: <HITACHI CDR-7930, , 1023> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 3, DMA mode 1
wd0 at pciide0 channel 0 drive 0: <IBM-DTTA-350840>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 8063 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 16514064 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2 (Ultra/33)
pciide0: primary channel interrupting at irq 14
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data transfers)
cd0(pciide0:0:1): using PIO mode 3, DMA mode 1 (using DMA data transfers)
pciide0: secondary channel configured to compatibility mode
wd1 at pciide0 channel 1 drive 0: <IC35L060AVER07-0>
wd1: drive supports 16-sector PIO transfers, LBA addressing
wd1: 58644 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 120103200 sectors
wd1: 32-bit data port
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
pciide0: secondary channel interrupting at irq 15
wd1(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using DMA data transfers)
...
Kernelized RAIDframe activated
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs
wd0: transfer error, downgrading to Ultra-DMA mode 1
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 1 (using DMA data transfers)
cd0(pciide0:0:1): using PIO mode 3, DMA mode 1 (using DMA data transfers)
wd0a: error writing fsbn 16 of 16-19 (wd0 bn 10249486; cn 10168 tn 2 sn 16), retrying
wd0: (aborted command, interface CRC error)
wd0: soft error (corrected)
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