Thanks for the note. I uploaded my icon to the correct directory and I can now use it. A couple of other issues have arisen.
1. After clicking my custom icon it actually disappears for a moment and then reappears. Tested it out on a few browsers and it happens on all of them. I tried one of your custom icons and the disappearing doesn’t occur. http://dev.fresnohousing.org/about/properties/
2. I have included a .shadow.png file in the same directory (the first part of the file name matches the icon file name) but it isn’t displaying at all.
Do you have any thoughts on fixes?