Raid 1 problems

[meliason at shaw.ca (Mace Eliason)]

Hi,

I have setup raid on a new server and have found that if I remove one 
drive it will boot but if I remove the other it says missing OS.

I am using two 18.2Gig SCSI drives, using software raid 1. 
I have it setup with the following drives in this order.

/boot
swap
/

all are mirrored between the two drives.  I remember a while back that 
their was a problem with grub would that be the problem here?
Why does it work on one drive and not the other?

Thanks

Mace