Continued looking today and it retrieved data in the RV View, which it didn't do yesterday.
Hmmmm....tired old server didn't like all open queries in SQL manager yesterday?
So that solves the problem. Had a look at the view code also and could verify that ther audit_trail table isn't used.
Thanks for the help. Wouldn't have looked in the views if you hadn't pointed it out. (Hope they get documented one day as it is a bit of a haystack.)