Thanks guys for all the advice with this. I've now nailed the problem. I ran the sim yesterday all afternoon with various aircraft in the ETO series with no problems. I've have to say yet again the cockpits and aircraft detail is quite remarkable and hats off to all you talented artisans and a big thank you for all the hard work invovled for creating them for us 'Brainless' ones

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No it seems the problem is with the aircraft. When I select the BOA Cat Attack 01 anti U-boat mission in the Battle of Britain era the Catalina aircraft produces the graphics corruption after running for a rew minutes. If I select the ETO Catalina IIa or the ETO Catalina MKIIIA the same thing happens but if I select the ETO Catalina..MKIII-A then everything runs fine with all the sliders maxed out.
Quite why this is I do not know as all the aircraft look very similar and the cockipits seem the same. Obviously there is either something missing in the aircraft files when I installed but I would have thought the sim would have identified that and thrown up an error message at start up or alternatively there is a compatability issue.
Maybe someone can try this mission on a different system and let me know if they have the same problem. If the I'm the only one with the issue then I will have to obtain revised aircrfat files from somewhere.
All the best and thanks again for the support.
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