When burning a CD on a 1.6 system, I got the following messages:

Oct 21 12:04:28 challenger /netbsd: cd1(pciide0:1:1):  Check Condition on CDB: 0x28 00 00 00 00 00 00 00 01 00
Oct 21 12:04:28 challenger /netbsd:     SENSE KEY:  Illegal Request
Oct 21 12:04:28 challenger /netbsd:      ASC/ASCQ:  Illegal Field in CDB
Oct 21 12:04:28 challenger /netbsd: 
Oct 21 12:04:28 challenger /netbsd: cd1: dos partition I/O error


The CD itself looks fine -- I ran md5 on each file on it, and it 
compares properly.  

Here's the relevant dmesg output; if it matters, this is an Athlon 
machine with a VIA chip set....  (But I never saw such messages on 
-current leading up to the 1.6 release.  It's now running 1.6.)

pciide0: primary channel interrupting at irq 14
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66) (using DMA data 
transfers)
pciide0: secondary channel configured to compatibility mode
atapibus0 at pciide0 channel 1: 2 targets
cd0 at atapibus0 drive 0: <LTN485, , KQ01> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 4, DMA mode 2
cd1 at atapibus0 drive 1: <Hewlett-Packard CD-Writer Plus 9500, YM5CJ58VA3, 1.0e
> type 5 cdrom removable
cd1: 32-bit data port
cd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2 (Ultra/33)
pciide0: secondary channel interrupting at irq 15
cd0(pciide0:1:0): using PIO mode 4, DMA mode 2 (using DMA data transfers)
cd1(pciide0:1:1): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data 
transfers)



		--Steve Bellovin, http://www.research.att.com/~smb (me)
		http://www.wilyhacker.com ("Firewalls" book)