Workload Analysis (SWI5) Vs WF Inbox Anomolies

[NICHOLAS HALLAM]

In both our QA and production environments we are finding that a given user may have a number of Work Items of which they are the agent (when looking at the Workload Analysis - SWI5), yet that same user has nothing in their Inbox (SBWP).
 
Has anyone any ideas how this may be happening, and also how to correct it?
 
Thanks in advance
 
..Nick
SAP Support
Westland Helicopters Ltd