Hi, thankyou Archie for the advice, however, it didn't work for me I'm afraid. Does nyone know what might be causing this? It's a real problem as I sometimes have a smaller image with a white or black background in the centre and adjust the desktop colour to match, so it appears full screen. With this issue going on, I can't do that anymore. Besides, it gives me a headache!

Many thanks again Archie!