sharding plugin - "ShardingDS.groovy: 15: Can't have an abstract method in a non-abstract class"

Install (as described in http://jeffrick.com/2010/07/13/a-grails-plugin-for-sharding/) on console:

1) grails create-app ShardingExample
2) cd ShardingExample
3) grails install-plugin sharding

than set up first domain class:
4) grails create-domain-class UserIndex

in this step the error occours:

C:\Dokumente und Einstellungen\soenkex\.grails\1.3.7\projects\ShardingExample\plugins\sharding-0.5\src\groovy\com\jeffrick\grails\plugin\sharding\ShardingDS.groovy: 15: Can't have an abstract method in a non-abstract class. The class 'com.je
ffrick.grails.plugin.sharding.ShardingDS' must be declared abstract or the method 'java.util.logging.Logger getParentLogger()' must be implemented.
@ line 15, column 1.
class ShardingDS extends AbstractRoutingDataSource implements ApplicationContextAware {
^
1 error
at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:302)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:969)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:519)
at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:497)
(....)

Thanks!
-Soenke