Hm, it copies the image with transparency and if the application cannot handle it or does handle it in a different way, the result is not satisfactory. There is no real standard for images with transparency in Windows clipboard. Hopefully the situation improves.
Cannot copy/paste an image selection from Paint.com into a RichE
Cannot copy/paste an image selection from Paint.com into a RichEdit control.
Paste seems to work fine in OpenOffice Writer, however multiple other apps (e.g. Thunderbird new email) either don't paste anything at all or do paste the image but 99% of it is completely blank (e.g. Wordpad)
Apart from that, v.cool tool π