When marking a task as complete I received a "too few paramaters" error for substr in "utf.php" on line 37. I noticed this function:

 
  function strlen_utf($string) {
    if(function_exists('mb_strlen')) {
      return mb_strlen($string);
    } else {
      return substr($string); <--- line 37
    } // if
  } // strlen_utf

Notice the second return, judging by the rest of the file I assume this was the intended structure:

  function strlen_utf($string) {
    if(function_exists('mb_strlen')) {
      return mb_strlen($string);
    } else {
      return strlen($string); <--- fixed line 37
    } // if
  } // strlen_utf

After the above change all is well - task completion works without errors.

PS: GREAT PRODUCT - I love it so far!