current-users: Why xmcd works but cdplay don't?

Subject: Why xmcd works but cdplay don't?
To: None <current-users@netbsd.org>
From: Rui-Xiang Guo <rxg@ms25.url.com.tw>
List: current-users
Date: 04/04/2002 21:16:47

Hi, all
both them will print out the messages, something like:

cd0(trm0:0:0:0):  Check Condition on CDB: 0x15 10 00 00 1c 00
    SENSE KEY:  Illegal Request
     ASC/ASCQ:  Invalid Field In Parameter List

cd0(trm0:0:0:0):  Check Condition on CDB: 0x15 10 00 00 1c 00
    SENSE KEY:  Illegal Request
     ASC/ASCQ:  Invalid Field In Parameter List

but xmcd still could play the audio CD.
The box is i386 with SCSI cdrom.
Could someone resolve this puzzle?

-rxg