It currently only has an icon in windows, I haven't gotten to the X icon yet. I'm pretty sure windows only supports .ico icons though.
I'm pretty sure Windows supports PNG, too. Anyway, it doesn't matter, it's probably best to have both anyway.
Those glitches do look pretty bad. Which wx platform are you using? I'm afraid I only tested wxGTK (and the one for windows).
Yeah, I'm using wxGTK
It looks as if some of the masks for the pieces are screwed up - the wrong areas are transparant. It is like this right when you start the game right? Or does it degrade when you start pulling stuff around?
Yeah, as soon as I pick an image and puzzle size they are screwed up. They stay in the same screwed up shape the whole time, it doesn't change or flicker or anything.
I also get this warning (which I noticed after initially posting the problem):
(jigsaw:20446): GLib-GObject-WARNING **: invalid cast from `GdkPixmap' to `GdkWindow'
I think it likely has something to do with whatever's wrong.