Vista - eSATA external HDD ok under XP, no longer activated under Vista x64

I have seen a thread about that, but since it's getting old, I wanted to post a new one to ensure it will be seen... Sorry for redundency if you have read it elsewhere.

I have a dual-boot PC (Win XP Pro 32 bit and VISTA x64). The Nextar3 plugged through eSATA (ASUS P5B) was seen until a few days ago when I updated BIOS (for another problem).

Since then, only XP sees the external drive (in a Nextar 3 encavure). Under Disk Management, I can see this ''disk 0'' (dynamic) as unactivated (in Vista) - I don't even see the two volumes on it anymore. (And the drive had been plugged there way after my Vista installation).

Under XP, I have no problem at all...

I have been trying to find a fix to that at Microsoft forums, and a few others as well, but the only reply was to convert to basix disk - which would then require to wipe out a few installations that I use only under XP...

And Microsoft knowledged base suggest to ''reactivate'' disk with a simple right-click, but I don't even see that option possible (it's not there, not even in grey !)...

Anyone finally found a fix to that ?

Thanks,
Rob