Weird behavior

Yesterday I was working on final graphics of our new Eclipse RCP based application (http://www.webload.org/ ). Among the icons, we have asked the designers to prepare an application window icons, which are set in the branding section of product configuration. The designers did a great job, the icon looks excellent.

But when we tried to put it in place, we have discovered that the dialog is only able to accept GIF format, nothing else.

The designers, have supplied the icons in the PNG format, clearly a much better suited for graphical work. I have asked them to convert the icons to GIF, and they said, "OK, which background would you like?". I didn't know. I said, well, I kinda need it transparent, to look good in the different versions of windows and in the Alt + Tab window, is that possible? They said "yes, it is". However, they said, there are no transparency levels, it is all or nothing. So, the icon looks pretty awful, especially when switching between applications.

Clearly I was not satisfied. I pointed at the eclipse icon, which looked great and asked them to make ours in the same way. The said that it could not be done with GIF and offered me a bet if I could find that icon in eclipse installation and show it to them. They sounded confident enough, so instead of taking the bet I have downloaded a small utility that can look into JARs and looked for all images called "eclipse" in the installation directory. I found quite a few GIFs, but none of them was what I was looking for. On the other hand, I found quite a lot PNGs, just like designers have said. I was very glad I did not take that bet but I still had a problem. How would I put PNG into a field that only accepts GIFs. One of the designers suggested that I put it there nonetheless. I was skeptical but decided to do it. It has produced an ugly warning, but, amazingly, it worked. The icon worked exactly as required.

Needless to say I was looking a little stupid, I also felt bad for eclipse, after all - what is that? I did not manage to find a good explanation for this strange behavior so far. Why would this dialog only allow to put GIF images and not PNG images that work much better. I will try to investigate this further and keep you posted but if by any chance you know the answer, or you know an already open bug on the subject please tell me.