You could try going into your Dashboard > Pages > Home then insert the image there rather than the actual post. Its practically the same as inserting an image into a post except your inserting it into the page rather than the post.
Hi Karma it was me it posted that sorry i didn’t realise you replied, i’m a bit stuck on where to put the Code you supplied as my style.css is very brief due to my theme.
I’m using the default buddypress theme if that helps?