Compiler error eclipse plugin

Hello,

First of all I must say I’m new to Vaadin, I discovered it two weeks ago, and I must say it’s great. Thanks for your work on it, and i hope i can help you when i get a little bit more experienced on it.

Here’s the issue, I’m trying to add an add-on (vaadin-timeline) to my project, following the video tutorial.
I’m getting this error (if i try with another add-on i get the same error).

Compiling widgetset com.example.ttt.widgetset.TttWidgetset
Updating GWT module description file…
07-dic-2010 14:59:05 com.vaadin.terminal.gwt.widgetsetutils.ClassPathExplorer getAvailableWidgetSets
INFO: Widgetsets found from classpath:
com.vaadin.terminal.gwt.DefaultWidgetSet in jar:file:C:/dev_vaadin/workspace/ttt/WebContent/WEB-INF/lib/vaadin-6.4.8.jar!/
com.example.ttt.widgetset.TttWidgetset in file://C/dev_vaadin/workspace/ttt/src

Done.
Starting GWT compiler
Loading module ‘com.example.ttt.widgetset.TttWidgetset’
Loading inherited module ‘com.vaadin.terminal.gwt.DefaultWidgetSet’
Loading inherited module ‘com.google.gwt.user.User’
Loading inherited module ‘com.google.gwt.core.Core’
Loading inherited module ‘com.google.gwt.core.CompilerParameters’
[ERROR]
Line 23: Unexpected element ‘define-configuration-property’
[ERROR]
Failure while parsing XML

I’m using Eclipse plugin, vaadin 6.4.8, and I can’t figure out what I am doing wrong.

Any help would be appreciated.

Thank you very much.