--- trunk/lib/Biblio/Isis.pm	2006/08/25 10:20:58	66
+++ trunk/lib/Biblio/Isis.pm	2006/08/25 16:35:47	67
@@ -599,7 +599,7 @@
 					next if (! $t);
 					my ($sf,$v) = (substr($t,0,1), substr($t,1));
 					# XXX this might be option, but why?
-					next unless ($v);
+					next unless (defined($v) && $v ne '');
 #					warn "### $f_nr^$sf:$v",$/ if ($self->{debug} > 1);
 
 					if (ref( $val->{$sf} ) eq 'ARRAY') {