PHP使用PDO连接sql2008时，出现这种编码错误，求解！

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[IMSSP]: An error occurred translating string for a field to UTF-8: �ڶ��ֽڵ�Ŀ������ҳ�У�û�д� Unicode �ַ�����ӳ�䵽���ַ��� ' in C:\wamp\apache\htdocs\xyjnew\admin_news2.php:39 Stack trace: #0 C:\wamp\apache\htdocs\xyjnew\admin_news2.php(39): PDOStatement->fetch() #1 {main} thrown in C:\wamp\apache\htdocs\xyjnew\admin_news2.php on line 39
这种错误不是经常出现，大概刷新个10次8次的才会出现一次，求指导什么原因，真心求教！