XP 32b and Vista 64b

[MonsterDK]

Hi,

I have Windows XP Pro 32bit and Vista Ultimate 64bit installed on separate HDDs.

I have the 6 HDDs in total installed...

WD 1TB
WD 1TB
WS 500Gb (Win XP Pro 32bit)
Hitachi 250Gb (Vista Ult 64bit)
Samsung 1TB
Samsung 1TB

The problem I have is that I have just lost the data on all my 1TB drives.
There was working fine. But since I have been into Vista (this has just been added to the system as a Dual boot) then back into Windows XP Pro. The 1TB drives was not showing in My Computer.
I looked in Computer Management ---> Disk Management to find that these 4 HDDs was showing as foreign.
I was unable to select the option to put them back online. I there for had to re activate the drives / partition then quick format :(

Now when I boot back into Vista Ult 64... I have the same issue there. The drives are not in My computer and there showing as foreign in Computer Management ---> Disk Management.

Can anyone shed any light on this please?
I have allot of important data backed up that I need to re-put back onto these drives but I need to know what the cause of this issue is.

Thanks in advanced.