SMP kernel freezes on Fujitsu-Siemens F250

Hello,

I've upgraded FreeBSD on one of our Fujitsu-Siemens F250 machine from a 
5-CURRENT (sometimes in October) to RELENG_5_2.

The 5-CURRENT from October worked fine with SMP enabled (the BIOS has a 
switch, APIC enabled and disabled), but does not start with ACPI enabled.

5.2-RC starts, but only in uniprocessor mode.

I've tried it in the following modes:
SMP enabled (APIC enabled):
	ACPI enabled, ATA controller enabled - failed to get to userland
	ACPI enabled, ATA controller disabled -failed to get to userland
	ACPI disabled, ATA controller enabled -failed to get to userland

SMP disabled (APIC disabled):
works in any constellation (with, or withour ACPI, ATA).

If SMP is enabled the machine freezes in two stages:
when ATA controller is enabled:

Timecounter "TSC" frequency 1796522368 Hz quality -100
Timecounters tick every 10.000 msec
lo0: bpf attached
ata1-master: pio=0x0c wdma=0x22 udma=0xffffffff cable=40pin
ata1-master: WARNING - SETFEATURES recovered from missing interrupt
ata1-master: setting PIO4 on ServerWorks CSB5 chip
acd0: WARNING - MODE_SENSE_BIG recovered from missing interrupt
ata1: resetting devices ..
ata1: reset tp1 mask=03 ostat0=50 ostat1=00
acd0: stat=0x00 err=0x01 lsb=0x14 msb=0xeb
ata1-slave:  stat=0x00 err=0x04 lsb=0x00 msb=0x00
ata1: reset tp2 mask=03 stat0=00 stat1=00 devices=0x4<ATAPI_MASTER>

When ATA controller is disabled:

Timecounter "TSC" frequency 1796521772 Hz quality -100
Timecounters tick every 10.000 msec
lo0: bpf attached
Waiting 15 seconds for SCSI devices to settle
(noperiph:sym0:0:-1:-1): SCSI BUS reset delivered.
sym0: enabling clock multiplier
sym0: Downloading SCSI SCRIPTS.

The kernel config is GENERIC.

Full boot logs can be found here:
http://k2.jozsef.kando.hu/~bra/fusi-freebsd/acpi-ata.TXT
http://k2.jozsef.kando.hu/~bra/fusi-freebsd/acpi-noata.TXT
http://k2.jozsef.kando.hu/~bra/fusi-freebsd/noacpi-ata.TXT
http://k2.jozsef.kando.hu/~bra/fusi-freebsd/noapic.TXT

I've also tried CURRENT without success.

Any ideas what should I try? The machine has the latest BIOS (upgraded 
because the freeze).

It seems that I can enter to the debugger, because the machine has an 
NMI button, so if it's needed, I can get some more info out of it.

Thanks,
-- 
Attila Nagy                                   e-mail: Attila.Nagy_at_fsn.hu
Free Software Network (FSN.HU)           phone _at_work: +361 210 1415/127
ISOs: http://www.fsn.hu/?f=download            cell.: +3630 306 6758