i have such situation (first channel i've "successfully" destroyed)

pciide0 at pci0 dev 7 function 1: VIA Tech VT82C586A IDE Controller (rev. 0x06)
pciide0: bus-master DMA support present
pciide0: primary channel configured to compatibility mode
pciide0: primary channel ignored (disabled)
pciide0: secondary channel configured to compatibility mode
atapibus0 at pciide0 channel 1
cd0 at atapibus0 drive 1: <E-IDE CD-ROM CR-850E, , Ver1.11> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
wd0 at pciide0 channel 1 drive 0: <ST320423A>
wd0: drive supports 32-sector pio transfers, lba addressing
wd0: 19536 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 40011300 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 4
pciide0: secondary channel interrupting at irq 15
wd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
cd0(pciide0:1:1): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)


everything works OK! but IDE led works strange when netbsd boots. it goes
on all the time until i put any CD in drive then it starts working OK.
i could then remove this CD and all is OK.

why?