there is another difference: vb->pack_start(GTK.Pixmap(px,bmp),0,0,0);
aparently the image needs to be added not only as a GDK.Pixmap to set_icon(), but also as a GTK.Pixmap to the window itself. no idea why that is.
greetings, martin.
No, I just did that because the original code had the icon added to the window also. I just did exactly what the original code did, just split it onto separate lines (and apparently added the bitmap to set_icon() also).