Dell CERC (aac driver) issue after upgrade to 6-STABLE

[Chris Knight]

I just purchased a Dell PowerEdge 1800 to replace my mail server.  It
has two 3.2 Xeon processors, 2G of ECC memory, and a Dell CERC SATA
RAID controller with two 160G Maxtor drives in a RAID 1 mirror.  The
Dell CERC appears to be an Adaptec RAID controller, and it is detected
by the aac driver.

I donwloaded the ISO for FreeBSD 6.0 i386 and installed it tonight. 
So far, so good.

I rebuilt the RELEASE kernel with SMP options.  So far, so good.

I synced to 6-STABLE, made world, recompiled the SMP kernel.

Now when I reboot I get to the detection of the RAID controller and my
screen is scrolling with the following errors:

aac0:  COMMAND 0xc6588000 TIMEOUT AFTER 559 SECONDS
aac0:  COMMAND 0xc6588000 TIMEOUT AFTER 579 SECONDS
aac0:  COMMAND 0xc6588000 TIMEOUT AFTER 599 SECONDS

Has anyone else encountered this problem?  What do I need to do to fix it?

-Chris