Problem resolved. It was a bad cable.

Thanks Dan for the quick replacement. You're a champion.

I have purchased a set of cables from idiagnostics including a modified ELM327. I have the full registered MES 2.5 software installed on a Windows 7 (64) laptop. When I do a scan using the green adapter it does pick up the Airbag, Dash and Body modules. It doesn't see the engine or any other modules...