0 - 1 of 1 tags for uowid

We have no events in the esm repository where the uowid is blank or null.  But, the 'Jobs' portlet displays a lot of rows with blank / null uowid, uowTS.  The "Status" column has a value of "NEW" in every case where the uowid is missing.  What is happening and how can I prevent this behaviour?  I tried adding a filter of UOWID <> '' or UOWID > 'a