Episode Butler needs a free port. If the port isn't available Episode Butler is unable to start. To start the Episode Butler with another port add '-p 8077' (or another number) as a parameter.
The added value of the Episode Butler is that it not only searches episodes for your favorite shows, but it also knows which episode you still require. A watchdog or rss-feed will also download episodes that are reposted but which you have already seen and/or downloaded.
Since shows probably aren't the only things you download from usenet you'll already have a download tool. Since most newsservers have limitations on the bandwith and/or connections, its better to have a single application downloading. Episode Butler can focus on its task of finding episodes and the download application can focus on its downloading task
When a season is added a lot of info is requested from TVRage and this might take a while.