OK, well, I used the veto oplocks on the ACT share only, for the file types used by ACT (there where quite a few) I also did the registry imports.
Its not really made much difference in that the loading time is slow (well, according to the client) Its quite a big db (34mb) you see the progress bar go 22%, 33%,44%,55% and so on. At about 99% it sits there for some time then the app front end fires up. I looked in the server logs and cant see anything I think are errors. We just put in a HP Procurve 1GB switch and all new 1GB Nic's
I only have the clients word for this difference in load time (compared to 2003 server we took out - long story) and they also report that once 2 or 3 people are logged in it gets slow and twitchy (like its 'catching up with itself')
Its version 6.0 ACT! if anyones got any suggestions on how to debug this I would greatfully give it a try (sorry, I know this is probably a Samba issue and not SME specific but there are some good people here

Am going back on site tomorrow...