I guess I must have, didn't realise that the document still pulled info from the original images so I often delete the folders with the resized images in (this is probably why I have had the problem before)
So I will have to go back resize all images and make sure they are kept safe in a folder until I have completely finished with the documents and the brief is done.
Sorry if this is all quite naive of me, I have never been taught how to use indesign I have learnt the majority myself, being the only creative for a small company it is hard for me to learn new things without someone else who has the experience to bounce off. I really appreciate all you guys on the Adobe communities as its the only way I can learn and progress with these programs.