Disk Mirror Set

[DOCpcman]

I have approximately 100 Proliant ML530 Servers, all runing Windows 2000 Server SP4 with Smart Array 431 RAID controllers. They all have the same disk configuration, 2 - 9.1 gig drives on Raid 1 / 3 - 18.2 gig drives on Raid 5.
Lately I have noticed that 4 servers with the RAID 1 set broken in the disk management utility in Windows. I reboot the server to the array utility and it shows the RAID 1 set ok. I have booted with a Bart PE CD and it to shows the RAID 1 set intact.
One server we reloaded, and everything's o.k.
Does anyone have a quick fix? I have searched Technet and HP's site, but came up empty handed.