This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Any particular reason you are using that repository and not Maven Central? Try removing the <repositories> section and see if that works. (Though having looked at the POMs in both locations, they appear to be the same, so I am confused as to why the parent seems to have a null group and version. You might try clearing out your local repository, or at leats the com/sun directory - could be that the local repository is corrupted.)