That's because you are trying to post a file directly off of your computer. You need to upload them to a gallery here on TRT or to somewhere like picturetrail (i hate photobucket)
As long as the bubble plate isn't going to float up into the reaction chamber when in operation it will be fine. Are you sure that it is cracked in half? Most of them are made in 2 pieces so they fit into the body through the neck of the skimmer ( although I do not have an MSX with a bubble plate, I have only seen pictures).
Go with the pinwheel, it will be better on you for startup issues and will not be too much for the skimmer
