Hi PowerPlanner, welcome to Sitepoint :).
You need to remove the list-style-type :). Well, also you need to make sure that your image file is correct. In your current CSS file (if it's not externally called), go to that folder. In that folder, you should have a folder called "Images" and in there has the bullet GIF.
Add this code in and the new bullet.gif should appear.
Though the missing image URL is the cause, since, if the image isn't found, it will just show the bullets. Please confirm the location of the URL is correct.