You may remember I emailed asking about using Windows Shadow Copy Client as I couldn't see any snapshots.
My config is
Filer: Data OnTap 7.0.0.1
Clients: Windows XP sp1 & sp2
Snapshots were set to visible from the web gui

Jourdan Bailey of NetApp found the solution that resolved the problem and allowed us to use the Win Shadow Copy client:
options cifs.show_snapshot on

Regards,

Iain Barnetson
IT Systems Administrator
UKN Infrastructure Operations