I am not sure if you are also passing through the same problem or not, but what my problem was all the images used to get showed up on our development server. But when we uploaded that on live, it was not being shown in either admin or on front end. The image URL was also the same from where I should be able to access the same image, But still the issue was there. We have checked all the permissions, increased the file upload size, but in vain.
The solution was just to rename .htacess to some name like .htacess_old.