diff --git mvf.module mvf.module
index 8340d15..1519065 100755
--- mvf.module
+++ mvf.module
@@ -161,10 +161,10 @@ function mvf_field_settings($op, $field) {
  * Implementation of hook_content_is_empty().
  */
 function mvf_content_is_empty($item, $field) {
-  if (empty($item['value'])) {
+  if ($item['value'] == '') {
     return TRUE;
   }
-  elseif($field['tovalue'] == 'required' && empty($item['value2'])) {
+  elseif($field['tovalue'] == 'required' && $item['value2'] == '') {
     return TRUE;
   }
   return FALSE;
@@ -185,7 +185,7 @@ function mvf_field($op, &$node, $field, &$items, $teaser, $page) {
     if (is_array($items)) {
       foreach ($items as $delta => $item) {
         // Empty "To" value should be saved equal to "From" value
-        if (empty($item['value2'])) {
+        if ($item['value2'] == '') {
           $items[$delta]['value2'] = $items[$delta]['value'];
         }
       }