Help getting RapidMinerGUI to run after import project into Eclipse

So, for reasons that can only be described as silly, I'm unable to use svn to load my project into Eclipse.  Instead I went to the SourceForge page and downloaded the file "rapidminer-5.3.005.zip" opened up the project and imported it into Eclipse as a pre-existing project.

Everything seems to show up fine, but I'm having trouble getting Eclipse to execute RapidMinerGUI.  I've set up a new Debug Configuration with the following info:

Project: RapidMiner_Unuk
Main Class: com.rapidminer.gui.RapidMinerGUI
Includes system library's when searching for a main class: yes
Include inherited mains when searching for a main class: yes
Stop in main: No

When I tell it to debug I get this error:

java.lang.NoClassDefFoundError: com/rapidminer/gui/RapidMinerGUI
Caused by: java.lang.ClassNotFoundException: com.rapidminer.gui.RapidMinerGUI
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)

For some reason it can't seem to see the RapidMinerGUI inside of the provided class file.  This is especially odd to me because I used a wizard to find the class...so it seems like if the wizard can see it, Eclipse should be able to as well.

Any thoughts?