freebsd stable - Apr 2005 - strange atacontrol output in 5.4-RC1 and 5.4-RC2

Hi,

I have two i386 computers with close configuration of ATA disks:

mercury# atacontrol list
ATA channel 0:
    Master:  ad0 <WDC AC14300R/17.01J17> ATA/ATAPI revision 4
    Slave:       no device present
ATA channel 1:
    Master:  ad2 <FUJITSU MPB3021ATU/2011> ATA/ATAPI revision 3
    Slave:  acd0 <TOSHIBA CD-ROM XM-6602B/1017> ATA/ATAPI revision 0

vega# atacontrol list
ATA channel 0:
    Master:  ad0 <WDC AC28400R/17.01J17> ATA/ATAPI revision 4
    Slave:       no device present
ATA channel 1:
    Master:  ad2 <WDC AC22100H/12.07H12> ATA/ATAPI revision 0
    Slave:   ad3 <Seagate Technology 1275MB - ST31276A/1.37> ATA/ATAPI
revision 2

Mercury is Intel SE440BX-2 motherboard based computer with FreeBSD
5.4-RC2. Vega is Intel 430TX chipset based computer with FreeBSD
5.4-RC1. When I run ' atacontrol cap 0 0' I get the same last part of
the output:

Feature                      Support  Enable    Value   Vendor
write cache                    yes      yes
read ahead                     yes      yes
dma queued                     no       no      0/0x00
SMART                          yes      yes
microcode download             no       no
security                       no       yes
power management               yes      yes
advanced power management      no       no      0/0x00
automatic acoustic management  no       no      0/0x00  0/0x00

How could the security feature be not supported and enabled at the same time?