Invalid workitem in UWL

Hi All,

User has invalid workitem in his UWL since August 2014. Task is not present in backend production R/3 systems swi5 inbox. At first, it was assumed it might be related to portal level cache but, the workitem still exists post clearing browser cache and manual refresh of UWL by user.

Their has been multiple portal restarts since August 2014 and portal was recently upgraded from 7.0 to 7.4 but issue still exists.

Regards,

Amit Nanda