Question : Problem: Drives boot on primary controller but not in RAID

I use my MSI motherboard RAID 0, Win XP SP2.  C, D, and E partitions.  I had one 250 and one 300 GB drive, but the RAID mirror used only 200 GB.  The  need for a larger C: partition became critical, so I obtained Acronis Disk Director Suite 10, based on their claim that it would resize partitions in RAID unlike Partition Magic which I had.  I found that the unused space was not visible using the RAID controller, even booting from an Acronis bootable disk; so I removed the drives from the RAID controller and put one on the primary controller - the unused space was now visible.  I used Acronis to create a new partition in that space, then gave part of it to the C: partition.  The result was just what I wanted.  

However, when I put that drive back on the RAID controller it would not boot; the RAID would complain about the broken mirror, I would continue with Esc, select Win XP, but then it would auto-reboot; over and over.  Eventually I thought that perhaps an intact array would help, so I put in a brand new drive and the RAID recovered the array successfully.  Try again to boot, no luck.  I have confirmed that either drive will boot with no problems from the primary controller, but not from the RAID controller.  The CMOS is set to boot from RAID first.  Presumably the RAID controller is OK because it did restore the array.

Another data point:  I am able to boot into RAID using the old 200 GB drive which I had removed.  Might there be a maximum ATA 133 RAID disk size <300 GB?  Also, if I boot with one of the "new" drives on the primary controller and another in the RAID controller:  it boots from the primary, but sees the RAID drive as 189 GB instead of 300 GB, and as a raw drive with no data...

Answer : Problem: Drives boot on primary controller but not in RAID

I was lucky to catch a technician at work at Promise, who builds the chip for MSI,  He suggested putting one drive on the RAID array, then removing/deleting the array (from the RAID startup menu).  It then automatically re-established that drive as a RAID 0 (single drive) which booted up OK!  I should now be able to re-establish the mirror and be back in business.  Apparently the array info on the drive(s) was corrupted, and deleting the array removed it (without affecting the data) - and replaced it with a usable, bootable configuration.