[Mustang1988]

Here is an easy way:

1. Instead of making the background transparent, make it some weird random color.

2. Save your image as a GIF file with Photoshop.

3. Close the untitled psd file without saving.

4. Open your saved GIF file in Photoshop.

5. Go to the save as GIF thing again.

6. It will let you use the eyedropper to select a color that will become transparent. Select the weird random color in the background, and hit OK!

7. Open it in Graal or whatever, and voila!