Likely this is simply the result of not matching the assembly of the jar file with your references. In other words, you indicated in Registry.dat that the icons can be found in a sub-directory /icons. My immediate guess is that if you remove this it will work. However, you can best determine why it is failing by looking at the Java Console on the client and the OHS logs on the server (assuming you are accessing via OHS). In the logs and console, if you look very carefully at the attempts to find your icons, not only will you see the HTTP 404 indicating they cannot be found, but you will also see exactly where the attempt was made to find it. My guess is that it isn't where you expect.
Also, there is no need to make any changes in the Windows Registry as these have nothing to do with runtime. Those changes are for the Builder only and not used for a running form.