http://www.dd-wrt.com/wiki/index.php/Tftp_flash

Special for Vista, Win7 and Win 2008
In order to catch the narrow window for TFTP flash, you should use platforms with simple TCP/IP implementations that don't have CTCP implemented
官方也是建議你關閉
我自己實驗過，也的確是刷了以後變磚

雖然內容說，不能確定所有機種都會這樣
但是碰到以後，你就有麻煩了