SMP goes away after installworld (4.8-STABLE)

[Mark Kent]

Hello,

I installed 4.8-RELEASE a few weeks ago, and since I let
the effort sit stagnant for a while I decided to do the 
cvsup/buildworld/buildkernel/installkernel/installworld/mergemaster/MAKEDEV
steps to get current.

Went fine, rebooted, then noticed that just one CPU was recognized:

 FreeBSD 4.8-STABLE #0: Thu Jun 19 17:05:20 PDT 2003 
     mark at lah-210.mainstreet.net:/usr/src/sys/compile/MDK 
 FreeBSD/SMP: Multiprocessor motherboard 
  cpu0 (BSP): apic id:  0, version: 0x00040011, at 0xfee00000 
  io0 (APIC): apic id:  1, version: 0x00170011, at 0xfec00000 

I confirmed my kernel config was OK, rebuilt it, rebooted
and got the same result.  I also looked at 'mptable' and 'top'
to make sure.

I boot off my backup disk and I get:

 FreeBSD 4.8-RELEASE #0: Thu May 29 14:48:37 PDT 2003 
     mark at lah-210.mainstreet.net:/usr/src/sys/compile/MDK 
 FreeBSD/SMP: Multiprocessor motherboard 
  cpu0 (BSP): apic id:  1, version: 0x00040011, at 0xfee00000 
  cpu1 (AP):  apic id:  0, version: 0x00040011, at 0xfee00000 
  io0 (APIC): apic id:  2, version: 0x00170011, at 0xfec00000 

So, there it is.  Both cpu (also present in mptable and top).
I confirmed that the kernel config is identical.

Any idea what I screwed up on the way to 4.8-STABLE that
lost me the SMP?

Thanks,
-mark