Problem with weather plug-in

This may or may not be a bug in Weather Monitor. This is what I am trying to do. Let's say I want to add more default icons in the skin.ini in order to get more types of weather. I add the icon name (for instance FreezingRain=freezingrain.png) to the skin.ini file. Then I open the wunderground.ini (if you are using this site) and add the heading [FreezingRain] and list Freezing Rain under it and remove Freezing Rain from the [Rain] heading. However, if <!-- w --><a class="postlink" href="http://www.wunderground.com">www.wunderground.com</a><!-- w --> lists Freezing Rain as the weather condition, no icon shows up in the Weather Monitor. But, it does show if I had left the files the way they were originally. Does this mean that we are unable to add additional icons and weather conditions? If so, will you enable us to add them in a future version?
???