Control issues using a PS3 controller

[Vexed]

Not owning an xbox, ages ago I DLed a program called SCPDriver to allow me to use my old PS3 controller as a 360 controller when in Big Picture Mode.

Having fond memories of Burnout I spent a couple of quid on this in the winter sale and was pleasently surprised when I dusted off my PS3 controller and found that I could load up and start the game with it. However I couldn't start the car, I could change songs open menus, change POV etc., but no button on the controller worked as accelerate.

Going into the controls menu I tried remapping R2 as accelerate and L2 as break and this worked to an extent. However as I am emulating an Xbox controller, the game reads these inputs as Z+ and Z- and says 'your accelerate and break are on the same axis' leaving me unable to start events or drift in game by pressing them both in combination.

I hope I've done a reasonable job of explaining the issue I'm having and someone more techsavvy than myself could suggest how to change what the game recognises as button inputs or a suitable controller configuration that will allow me to brake and accelerate simultaneously.

Thanks.