External HDD WIN7 Formatted XP can't read it...

Hi

Please accept my appologies if this is a known and solved issue that I haven't found yet.

I formatted my Western Digital 500GB My Book with Windows 7 RC and copied all my data across my network from my mac's external HDD. I'm sure I formatted it in NTFS and not the new Windows7 FAT32 replacement.

I needed to acces the files at work so brought the My Book into work.
I can't get my work XP laptop to see the partitions on the My Book -- it sees them in Disk Manager as Healthy (Unknown Partition) :-(

My work Vista64 machine sees similar in Disk Manager too.

I tried to find solutions on the web but only found people having problems reading XP formatted on Windows7.

Any help or links to solved similar problem gratefully accepted.

Is the drive accessible on the windows 7 machine still?