Workflow item doesn't appear under workitem assign to queue group

Just wondering if someone can help me please. We have got a workflow on vendor invoices which is working fine. However, there is an issue. A user can see the work item which has been assign to him under /Home/Common/Work items/Work items assigned to me. But, if he wants to see whatever assign to queue there is nothing under Home/Common/Work items/Work items assigned to my queues. . I have done some investigation and figure out that there is a table called WorkflowQueueDocumentCommonFields behind the form WorkFlowWorkItem. This table is not being populated for some reason. Can someone please help ?