cannot run full scan from the command line

I've WXP and a fresh installed Windows Defender 1.1 (so not the beta version)
I try to run a full scan from the commandline.
From the help (mpcmdrun -h) I understand that
>mpcmdrun -Scan -2
should do the work. But it doesn't, it runs a quick scan only.
It takes 30-40 secondes, I see no results in the .../Results/System folder,
but I do see them in the .../Results/Quick folder.
I've tried several variations on thsi command, no result so far.
Should this work?