Nice work Peter. The tones and detail in the nebulosity are just fabulous and the resolved stars of the Trapezium a real treat to see at the same time, in the same image.
Thanks all for the comments. M42 is a great target for HDR and also good for a moon lit night.
Geoff, I stacked the individual exposures in DSS, then did a quick levels adjustment in PS and then converyed the individual 9 images to a single HDR image using easy HDR.