Cryptic dependency error message

I'm trying to create a custom editor presentation plug-in. Using the following code (taken from the CalucatedRiskPresentation example), I'm getting this error message (see message under the code). Can anyone tell me what library I'm missing? This is for RTC 2.0.0.1. I have added just about every JAR under my Team Concert directory to the required libraries, but still no luck.

Thanks,

David

protected IAttribute getAttribute(String identifier) {		

	if (fWorkingCopy == null)

		return null;

	

	WorkItemUIWorkingCopy uiWorkingCopy= (WorkItemUIWorkingCopy) fWorkingCopy.getAdapter(IWorkItemUIWorkingCopy.class);

	return uiWorkingCopy.getResolvedWorkItem().findAttribute(identifier)

}

Error occurs on the return statement.

Error Message:

Access restriction: The method findAttribute(String) from the type ResolvedWorkItem is not accessible due to restriction on required library D:\<pathToTeamConcert>\jazz\client\eclipse\jazz\workitem\eclipse\plugins\com.ibm.team.workitem.client_2.0.1.I200909022001.jar