When you go to your settings area in your CMS Admin area, (settings.php), check to see what your uploaded files folder is. It will show a full server path to the file you specified during set-up, - something like /home/users/uks12345/html/yoursite.com/CMS/files.
First check that the file is on your server at that path, and also check that the folder has adequate write permissions (maybe 767).
What happens when you try to upload an image, and are you able to browse to your files folder? Do you get any error messages?
Also, what are all the other issues with the functionality?