To be honest, Brian, I have no clue what I've actually done! I went to make a cuppa, came back, took a breath and closed the Finder down. I then re-opened the Finder, went to the folder again (still wouldn't let me move or copy the images), so I somehow managed to drag the whole folder onto my desktop and access it from there... Wish I knew what I've done though! haha
Thank you anyhow for your reply