What do you know .... turns out I had a duff copy of the patch! I had created a nice fresh install to play with, to make sure I had no hidden twekas or text messing..... and had re-downloaded the patch. When I re-traced my steps. I found the game crashed as soon as I installed the patch...and the unpacking was nothing to do with it! I still got the crash.

Fresh download, and the thing works a treat now.... wierd or what! This is the first time I have had a bad download that extracted perfectly and ran ok.... live an learn