Index: sites/all/modules/link/link.module
===================================================================
--- sites/all/modules/link/link.module	(Revision 2438)
+++ sites/all/modules/link/link.module	(Arbeitskopie)
@@ -350,13 +350,18 @@
 
   // Add attributes defined at the widget level
   $attributes = array();
-  if (!empty($item['attributes']) && is_array($item['attributes'])) {
-    foreach ($item['attributes'] as $attribute => $attbvalue) {
-      if (isset($item['attributes'][$attribute]) && $field['attributes'][$attribute] == 'user') {
-        $attributes[$attribute] = $attbvalue;
-       }
-     }
-   }
+  // Check for non-empty serialized attribute string 
+  if (!empty($item['attributes'])) {
+    // unserialize attributes
+    if (!is_array($item['attributes'])) $item['attributes'] = unserialize($item['attributes']);
+    if (is_array($item['attributes'])) {
+      foreach ($item['attributes'] as $attribute => $attbvalue) {
+        if (isset($item['attributes'][$attribute]) && $field['attributes'][$attribute] == 'user') {
+          $attributes[$attribute] = $attbvalue;
+        }
+      }
+    }
+  }
   // Add attributes defined at the field level
   if (is_array($field['attributes'])) {
     foreach ($field['attributes'] as $attribute => $attbvalue) {