John - these are the settings I've got at the moment - mostly default. I tried tinkering with them as a result of suggestions made earlier in this thread, but somehow I must have gotten the wrong ones and it only made matters worse.

btw - I admit to being quite stupid about hardware, and easily confused if there is more than one setting required to achieve a single outcome!

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Which is the one I need to increase?

This is all I know how to reveal about my system...

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