GdkPixbufAnimation* test =
	gdk_pixbuf_animation_new_from_file("explode2.gif");
/* gif attached, each frame replaces previous */

GdkPixbufAnimationIter* iter =
	gdk_pixbuf_animation_get_iter(test, <time1>);
gdk_pixbuf_animation_iter_advance(iter, <time2>);
pixbuf = gdk_pixbuf_animation_iter_get_pixbuf(iter);

Now gdk_pixbuf_get_has_alpha(pixbuf) returns TRUE.
That's correct (it has), but alpha channel just contains
all 0xFF, instead of expected mask.

(gdk_pixbuf_add_alpha(pixbuf, TRUE, r, g, b) do the trick, ugly)