--- custom_formatters.module
+++ (clipboard)
@@ -458,7 +458,8 @@
   $full->tokens = array_merge($full->tokens, array_keys($tokens));
   $full->values = array_merge($full->values, array_values($tokens));
 
-  return _token_replace_tokens($formatter->code, $full->tokens, $full->values, '[', ']');
+  $tokens = token_prepare_tokens($full->tokens, TOKEN_PREFIX, TOKEN_SUFFIX);
+  return str_replace($tokens, $full->values, $formatter->code);
 }
 
 function _custom_formatters_tokens_list($field) {