Kevin,

>My views are all set to NODATA, apart from a view lookup views, and are only REQUERIED when necessary parts of the form are activated.

Are all 50 views opened when the form instantiates? Have you considered some kind of scheme that keeps a local copy of the DBC, to see if lots of the slow traffic is related to getting view definitions from the DBC as each is opened?
I really don't know exactly how that works, so I don't know if that's the problem, but I think I'd be curious enough about it to experiment.

I think you have to keep digging and testing things to determine just WHAT is taking so long.

Have you considered Terminal Server / Citrix for the slow network sites?