>I've had a brief look at the code to see if I can see where it's going
wrong
>but didn't spot anything, do you have any ideas?

I'm not sure if this will help, but the code does(has) work(ed) OK as I use
this feature on the Hydra build. Of course it might break when compiled
differently, but it does pick up the build type from the saved params file
at boot and passes the parameter to Linux which then uses this correctly.

Cheers

David.