Whats the 'feel' pf the lever when you go for reverse Mick - does it feel loose or different somehow?
Its possible there's a cable disconnection at the bottom of the gearstick.
John
i think you need to reveal the mechanism at the bottom of the gear stick Mick.....there's a series of cables there, connected to swivelling ball joints and its possible that one has come undone.
The same applies at the gearbox end, and any failure should be visible.
John