Index: core/cfdefs/cfdef_mantisuser.php
===================================================================
--- core/cfdefs/cfdef_mantisuser.php	(révision 35921)
+++ core/cfdefs/cfdef_mantisuser.php	(révision 35968)
@@ -130,7 +130,7 @@
  */	
 function get_mantisuser_threshold($p_field_def) {
 	$t_threshold = ANYBODY;
-	$t_possible_values = explode( '|', $p_field_def['possible_values'] );
+	$t_possible_values =  (strlen($p_field_def['possible_values']) > 0) ? explode( '|', $p_field_def['possible_values'] ) : array();
 	// the first possible value is the minimum userlevel for the mantis user
 	if ( count( $t_possible_values ) > 0 ) {
 		$t_threshold = constant_replace( $t_possible_values[0] );