Just to clarify...
Go to edit an existing product and scroll down to the image section.
To the right hand side of the 'Browse' button the existing image path will be displayed.
If the image is uploaded to your 'images' directory then it will simply display 'your_image.jpg' (where your_image is the name of the image).
If you uploaded the images to a subdirectory of the Image folder e.g. yoursite/images/coffee then it will display 'coffee/your_image.jpg'
To the right of the image path is also a drop down box that confirms where the image is stored.
Additionally, check there are no spaces in the file name and also be aware of case sensitivity....
Check the folder permissions of the IMAGES directory... mine are set at 755