Struts2 Dispatcher initialization failure with maven - jetty

I have the following problem:

I am working on a Web-Project using Struts2 with Tiles supported by a combination of Hibernate and Spring. In addition I am using Maven (which I'm new to) and the jetty server container. So my coworker told me what to do: just check out the project from the svn-repository and run the command (sudo) mvn jetty:run. According to my coworker this should work just fine, as it does when he checks out the project. But I always get the same error开发者_StackOverflow社区:

2011-08-22 10:09:20,568 ERROR org.apache.struts2.dispatcher.Dispatcher.error:38 -  
Dispatcher initialization failed
Unable to load configuration. - [unknown location]

I already tried to re-check out the project, cleaned and updated maven, but still, the same error.

I think it has something to do with a missing struts2 .jar-file, but I thought maven downloads all necessary libraries automatically. Please give me a hint what could be missing, I'm sure it's something simple I overlooked.

Thanks in advance.