IWorkItem.setValue() not persisting

Hi-

I've got some code to update a child workitem attribute. The code executes without error, and the update seems to work in the console output. However, when queried in the editor the old value is still present.

...
IAttribute summary = workItemServer.findAttribute(projectArea, "summary", monitor);
IWorkItem childItem = (IWorkItem)item.getFullState().getWorkingCopy();
...
System.out.println("AttrValue: " + childItem.getValue(summary)); >>outputs current value
childItem.setValue(summary, "test");
System.out.println("AttrValue: " + childItem.getValue(summary)); >>console correctly shows 'test'

Missing anything in the implementation to persist the change?

Thanks