taskdef A class needed by class com.ibm.team.build.ant.task.

I am trying to follow this article to integrate RTC and CruiseControl, but get this error below at this line:
<import>
taskdef A class needed by class com.ibm.team.build.ant.task.StartBuildActivityTask cannot be found: com.ibm.team.build.internal.scm.RepositoryManager$IConsole
https://jazz.net/library/article/350/#How_does_the_Hudson_RTC_Build_Work
http://i56.tinypic.com/28vudz9.png
<import>
taskdef A class needed by class com.ibm.team.build.ant.task.StartBuildActivityTask cannot be found: com.ibm.team.build.internal.scm.RepositoryManager$IConsole
https://jazz.net/library/article/350/#How_does_the_Hudson_RTC_Build_Work
3 answers

Hi Jirong,
please follow the following topic and copy the Task Definitions into your ANT script:
http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0m1/topic/com.ibm.team.build.doc/topics/r_ant-tasks.html
I don't get it. In the follow image, the JUnit sample build runs fine but has the same issue. The taskdef is already in the build.xml (I didn't do anything) Something else is missing.

Hi Jirong,
please follow the following topic and copy the Task Definitions into your ANT script:
http://publib.boulder.ibm.com/infocenter/clmhelp/v3r0m1/topic/com.ibm.team.build.doc/topics/r_ant-tasks.html
Got it, there is a line in this paper:
Open BuildToolkitTaskDefs.xml and find the taskdef for startBuildActivity. Copy it and paste it into your build.xml.
You may see the following warning. You can safely ignore it. It is due to an Eclipse problem with taskdefs.
taskdef A class needed by class com.ibm.team.build.ant.task.StartBuildActivityTask cannot be found...
https://jazz.net/wiki/bin/view/Main/AntBuild