What about starting the machine without the 300GB internal drive, so that the stone then becomes broke and blank.
Also have you just tried adding just one drive from the array, no spare, no parity.
[Edit]
Think many people understand how temperament sw_config can be at times. I have just tried to add a second device (SCSI external array) as a second partition and it complained about the first partition being too big.. even though, the first partition has been up and running for months... ARGGGGGG!! So I gave up, after all I was only doing it to check the throughput.
