No, in GIMP there is also a transparent layer underneath if you choose a transparent background for your image, but it is not editable, it's invisible. You don't ADD a transparent layer in Photoshop either, it's there from the beginning. It's a matter of definition. Point is, anyway, that Photoshop is even easier than GIMP to create transparent images with, simply because there is always a transparent background, in GIMP you have to specify the transparency BEFORE you start making the image. I'm guessing what Silvenon did, was to 'Flatten Image' and that essentialy means remove transparency and layers- ie put it all onto a 2D environment, or on a piece of paper if that's clearer. What you need to do is 'Merge Visible' and then save as .png or other formats that support transparency and internet readability.