Quote - @ MaskimXul: Yup, it's broke. For a work around you can use TIFF as it saves correctly. I'll file this as a bug. Hopefully SR3.

When you hit something like this,especially if you can reproduce it file a bug report. They really do read those and that's the best way to get your pet bugs fixed.

Thanks. It's a big issue for me, because of rendering png thumbs for my products.
I've been exporting them as jpg and then converting them as png.
Converting thumbnails is a bit annoying, but ah well, I will submit a bug report and hopefully that will be addressed sometime in the near future.