Getting SMP working

The hardware platform:

MB:  ASUS M2V AM2 skt940 VIA K8T980 PCI-Ex16 SATA RAID GigaLAN
CPU: AMD AM2 Athlon 62 X2 4600+
RAM: Geil Ultra DDR2 1GB PC6400
VGA: Asus Extreme X300SE 128MB DDR
HDD: 320GB Hitachi Deskstar SATA 2 300 16MB cache

The software:
eCS 2.0 Beta 4

I enabled all the relevant options during the install for SMP
operation.

After the three phase installation and the final boot up I have one
processor/core
being initialised(no apologies for English English spelling) - fine.

I then proceed to edit the PSD driver line in c:\config.sys to add the option
/SMP
and then reboot.

eCS just sits there at the boot splash screen. I have to boot to a command
line,
edit config.sys and remove the /SMP option and then everything is fine again on
one
processor/core.

Any clues?