--- mantisbt-1.2.3-orig/core/filter_api.php	2010-09-14 20:40:10.000000000 +0200
+++ mantisbt-1.2.3/core/filter_api.php	2010-11-26 10:58:46.000000000 +0100
@@ -1944,8 +1949,10 @@
 				' OR ' . db_helper_like( "$t_bug_text_table.description" ) .
 				' OR ' . db_helper_like( "$t_bug_text_table.steps_to_reproduce" ) .
 				' OR ' . db_helper_like( "$t_bug_text_table.additional_information" ) .
-				' OR ' . db_helper_like( "$t_bugnote_text_table.note" );
-
+				' OR ' . db_helper_like( "$t_bugnote_text_table.note" ) .
+				' OR ' . "($t_bug_table.id IN ( SELECT DISTINCT bug_id from " .
+				db_get_table( 'mantis_custom_field_string_table' ) . " where value LIKE '%$c_search%'))";
+				
 			$t_where_params[] = $c_search;
 			$t_where_params[] = $c_search;
 			$t_where_params[] = $c_search;