ad3 turns to ad1 after kernel update

[Jozef Babjak]

Hi all!

I updated kernel on my system:

[babjak]{~}<7:32:39>uname -a
FreeBSD cronin.chtf.stuba.sk 4.9-STABLE FreeBSD 4.9-STABLE #0: Mon Jan 12 16:03:27 CET 2004     
root at cronin.chtf.stuba.sk:/usr/src/sys/compile/KERONIN  i386
[babjak]{~}<7:32:41>

I have one CD-ROM and two hard disk which is connected:

  PRIMARY MASTER: HD Western Digital Caviar 40GB (this holds system)  
   PRIMARY SLAVE: none
SECONDARY MASTER: CD-RW PLEXTOR CD-R PX-W5224A
 SECONDARY SLAVE: HD Western Digital Caviar 6.4GB (backup files)

The smaller disk was /dev/ad3 before, but after the kernel update it turns to /dev/ad1. 
Why? (When I boot a GENERIC kernel now, the disk is /dev/ad3 back.)

Jozef Babjak.