You know how at the start of this I said it might be something incredibly newbish?

Well.. I bought another training book this weekend, one which inlucded the cruicial line that no other book so far had said...

"IPR is a photo realistic test render for previews. In order to render fully go to the render menu.. " etc etc....

Yes, I thought that IPR was full render and the little button next to it was preview...

Sorry folks