2.6.31: booting on a PIII Celeron?

[Michael Tokarev <mjt@tls.msk.ru>]

Hello.
I've a problem here with 2.6.31.  kernel is
compiled for PIII:

  CONFIG_MPENTIUMIII=y
  CONFIG_X86_GENERIC=y

This kernel works on real PIII machine - like this:

vendor_id	: GenuineIntel
cpu family	: 6
model		: 8
model name	: Pentium III (Coppermine)
stepping	: 10
cpu MHz		: 997.580

But it fails on a Celeron:

vendor_id	: GenuineIntel
cpu family	: 6
model		: 8
model name	: Celeron (Coppermine)
stepping	: 6
cpu MHz		: 797.481

it fails on early boot, after a bootloader printed
"Loading kernel... initrd..." -- after that, on the
Celeron machine, it reboots instantly.

It's the same kernel binary, I tried it on several
machines, and the result is pretty consistent - if
it's a PIII-Celeron it reboots, if it's a PIII -
kernel boots and works ok.

All previous kernels with the same config worked on
these machines, at least as far as this issue is
concerned.

Is it a known issue?  Is there anything else I can
try to debug it?

Thanks!

/mjt