It looks as though you have made some modifications to the map on the page. Were you able to get the map to display properly on the page before making any edits to it? Have you tested all of these locations individually to ensure that they are valid?
If you have a working map and would like to customize the images used for the markers that should not be a problem, you just need to ensure that you are starting with a working map. Please post back with this info and any other details you can come up with so we can help you out.