cdrecord, CD-R error messages with 7.0-RELEASE

[Walker]

When trying to burn an ISO with cdrecord:

cdrecord -v -sao fs=32m dev=1,0,0 speed=24 7.0-RELEASE-i386-disc1.iso

I'm seeing these syslog messages:

Mar  9 12:40:06 <kern.crit> server kernel: acd0: FAILURE -
MODE_SELECT_BIG ILLEGAL REQUEST asc=0x26 ascq=0x00 sks=0x00 0x00 0x0c
Mar  9 12:40:06 <kern.crit> server last message repeated 2 times
Mar  9 12:40:06 <kern.crit> server kernel: acd0: FAILURE -
MODE_SELECT_BIG ILLEGAL REQUEST asc=0x26 ascq=0x00 sks=0x00 0x00 0x0a
Mar  9 12:40:06 <kern.crit> server kernel: acd0: FAILURE - READ_BUFFER
ILLEGAL REQUEST asc=0x20 ascq=0x00
Mar  9 12:40:06 <kern.crit> server kernel: acd0: FAILURE - READ_BUFFER
ILLEGAL REQUEST asc=0x20 ascq=0x00
Mar  9 12:40:16 <kern.crit> server kernel: acd0: FAILURE - READ_TOC
ILLEGAL REQUEST asc=0x24 ascq=0x00 sks=0x40 0x00 0x02
Mar  9 12:43:32 <kern.crit> server kernel: acd0: FAILURE -
MODE_SELECT_BIG ILLEGAL REQUEST asc=0x26 ascq=0x00 sks=0x00 0x00 0x07

The two CD-R's I've recorded verify with an md5 okay.  Any ideas about
these error messages?