It looks like you have edited one of the files that is included in every page and added in the following
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-2" />
This is now appearing at the top of every file in your newspad installation including the RSS Feed. As the RSS Feed is XML it is very strict on what you can and can't have in the file and this extra code is breaking the RSS Feed from working.
You will need to locate the file that you have modified to add in this code and remove it. Your RSS Feeds will then work and so will the display within your forum.