Show NULL values AS not working

Hi Dave and team,<br /><br />Another slight bug (I think):<br /><br />I have a table which has a column called
"first_invalid"which should be a timestamp if the record is invalid, or NULL if it's valid.<br />In PgAdmin I have the
"ShowNULL values as <NULL>" option enabled, but it still displays a blank cell for this column. <br /><br />The
reasonwhy I think it may not be a bug, is I tried doing this:<br /><br />"SELECT COALESCE(first_invalid,
'<NULL>')AS first_invalid FROM table"<br /><br />but PostgreSQL threw it out because "<NULL>" is not a
validtimestamp - instead I had to do: <br /><br />"SELECT COALESCE(first_invalid, '1900-01-01') AS first_invalid FROM
table"<br/><br />to prove the column is in fact NULL, and I do get: "1900-01-01 00:00:00+00" for this record, but in
thedata entry grid, PgAdmin still displays it blank. <br /><br />Question: is this a bug, or intended behaviour?<br
/><br/>Thanks,<br /><br />Andy<br />