After updating the STK from version 1.0 to 1.1 on start up of magnolia this error occurs:

2009-04-03 15:54:25,792 WARN info.magnolia.commands.CommandsManager : Was not able to register [/modules/data/commands]
java.lang.ClassCastException: info.magnolia.module.data.commands.ImportCommand
at info.magnolia.commands.CommandsManager.registerCatalog(CommandsManager.java:93)
at info.magnolia.commands.CommandsManager.onRegister(CommandsManager.java:82)
at info.magnolia.commands.CommandsManager.onRegister(CommandsManager.java:86)
at info.magnolia.commands.CommandsManager.onRegister(CommandsManager.java:86)
at info.magnolia.commands.CommandsManager.onRegister(CommandsManager.java:86)
at info.magnolia.cms.beans.config.ObservedManager.register(ObservedManager.java:85)
at info.magnolia.module.ModuleLifecycleContextImpl.initEntry(ModuleLifecycleContextImpl.java:93)
at info.magnolia.module.ModuleLifecycleContextImpl.start(ModuleLifecycleContextImpl.java:85)
at info.magnolia.module.ModuleManagerImpl.startModules(ModuleManagerImpl.java:349)
at info.magnolia.module.ui.ModuleManagerWebUI$1.exec(ModuleManagerWebUI.java:104)
at info.magnolia.context.MgnlContext.doInSystemContext(MgnlContext.java:377)
at info.magnolia.module.ui.ModuleManagerWebUI.execute(ModuleManagerWebUI.java:101)
at info.magnolia.cms.filters.InstallFilter.doFilter(InstallFilter.java:95)
at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:70)
at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:82)
at info.magnolia.cms.filters.MgnlFilterChain.doFilter(MgnlFilterChain.java:84)
at info.magnolia.cms.filters.CompositeFilter.doFilter(CompositeFilter.java:64)
at info.magnolia.cms.filters.AbstractMgnlFilter.doFilter(AbstractMgnlFilter.java:70)
at info.magnolia.cms.filters.MgnlMainFilter.doFilter(MgnlMainFilter.java:96)
at info.magnolia.cms.filters.MgnlMainFilter.doFilter(MgnlMainFilter.java:199)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:613)