Re: Same filename, different category.
Did you read my answer? =) I said SUffixed!
Let me explain it better.
If your userid is 318, your images are uploaded to "gallery/files/3/1/8/file.ext"
If you image is called "nice flower #3.jpg" it will be renamed to "niceflower3.jpg"
If you upload a new image called "niceflower3.jpg", and already exists a "gallery/files/3/1/8/niceflower3.jpg", the new image will be renamed "niceflower3_7864.jpg" where 7864 is a random number.