Hmm.. do you need apostrophes around the string constant you are matching against?

my $quote = $dbh->dbquote( $uname );

my $sql = <<SQLCODE;
SELECT
  uname
  ,pwd
FROM
  login
WHERE
  uname=$quote
SQLCODE
[download]

or

SELECT
  uname
  ,pwd
FROM
  login
WHERE
  uname='leander\@whatever.com'
SQLCODE
[download]

Finally a more obvious question, most DBs are case sensitive on searches, could this be a contributing problem?