Are you sure that the grey you see is actually in the image, or is it just how the 2D program displays the transparent area?

To test it, save the file from the program and see if it appears correctly in explorer, etc.

Many 2D paint programs will allow you to change how transparency is displayed in the document window.

---

Some things are easy to explain, other things are not........ <- Store ->   <-Freebies->