My Raid 5 array dissappeared on Vista 32

Hello,
my problem is that my Raid 5 array has been dissappeared while I was installing an old disk back. Here's what happened:
1. I had a system Disk which had two partitions and Vista Ultimate 32 installed on C: partition. Also I had a 3 disk RAID 5 array controlled by Silicon Image controller on my Intel 975XBX motherboard.
2. System disk had gotten a strong trojan which could not cleaned by ESET. I have disconnected this drive and installed a brand new drive, installed OS and other softwares.
3. I have re-connected my old disk with two partitions and re-scanned with ESET and cleaned the trojan. After this I have wanted to re-organize my drive letters for all my disks and DVD drives into a more sensible order.
4. First, I moved my DVDs to letters W: and Y: in order to be able to assign letters D: and E: to my old system disk and RAID array respecively.
5. RAID array was functioning just fine up to this point. I have re-booted my PC and my RAID array was missing from the Windows Explorer. I have checked the Disk Management/Storage and there it was, saying Healthy and Dynamic. But the drive letter was gone.
6. I have re-booted and gone in to Silicon Image manager and there was no problem with the array itself.
7.When done booting I re-checked the drive on Disk Management and the array was showing "Unallocated".

I suspect that this is something related with MBR or such.

How can I get my data back? Any help is appreciated...