Unable to find 'com/extjs/gxt/ui/GXT.gwt.xml' in GXT sample application - eclipse

Question

I'm trying to run a sample application using GXT (ExtJS + GWT) as described in the tutorial at
http://www.sencha.com/learn/setting-up-your-first-ext-gwt-project-in-eclipse
When I try to run the application in eclipse, I get the error
Loading modules
com.hello.gxt.HelloGXT
Loading inherited module 'com.extjs.gxt.ui.GXT'
[ERROR] Unable to find 'com/extjs/gxt/ui/GXT.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?
[ERROR] Line 15: Unexpected exception while processing element 'inherits'
My build path looks like this
and the build path of the run configuration looks like this
Here's the source: https://dl.dropbox.com/u/11776689/2012_09_27_HelloGXT.zip
How can I fix the problem?
'Update 29.09.2012': The former error is fixed, but now I get another one:
Loading modules
com.hello.gxt.HelloGXT
Loading inherited module 'com.sencha.gxt.ui.GXT'
Loading inherited module 'com.sencha.gxt.data.Data'
Loading inherited module 'com.sencha.gxt.core.Core'
[ERROR] Unexpected error while processing XML
java.lang.NoClassDefFoundError: com/google/gwt/core/ext/Generator
at java.lang.ClassLoader.findBootstrapClass(Native Method)
at java.lang.ClassLoader.findBootstrapClassOrNull(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)

Answer 1

Change your *.gwt.xml file from:
<inherits name="com.extjs.gxt.ui.GXT" />
to
<inherits name='com.sencha.gxt.ui.GXT' />
The tutorial you used is definitely for version 2.0. From GXT 3.0, the namespace changed to com.sencha.gxt...
UPDATE - to answer the next issue:
I think you are missing gwt-dev.jar
See this for reference: http://www.sencha.com/forum/showthread.php?73617-GWT-1.64-Class-not-found-exception-GXT-module-declaration-is.