Blue Screen of Death. Serial.sys driver problem on multi processor PC.

Hi all,

I have multiport PCI card with 8(16) serial port (UART).
These ports occupy one PCI BAR and I use mf.sys driver
for virtualise each port for Serial.sys
Serial.sys stands on each port very nice.
I deal with Windows 2000 or Windows XP.

This scheme works fine on uniprocessor system
even when I loading CPU to 100% (by reading CDROM and
running loopback test on each UARTs),
but when I setup PCI Multiport on system
with two CPUs and loading CPU to 100% PC hangs (Blue Screen of Death).
(Before hang LoopBack test generates errors. For example,
1000 byte wrote 800 received, or sync error.)

I took Windows XP DDK and compile serial.sys from this one.
No effects.

I think I must SpinLock something in WinXP DDK's Serial driver and
all be fine, because some datas already SpinLocked.
But I have no idea which one.

Please, help me to resolve this problem.

Best regards,
Alexandr Kouchtch