Duemilanove "L" LED between PIN 13 and TX LED keep flashing (non-stop)

My Duemilanove "L" LED between PIN 13 and TX LED

1.keep flashing when try to upload script
screen display error
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: Send: Q [51] [20]
avrdude: Recv:
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

  1. When i press reset it will keep flashing (non-stop)
  2. Unplug and plug again the it will keep flashing (non-stop) again.

Can anyone help ?

Hello,

Read this.

Hoping it will help.

Link corrected with the help of CrossRoads.

Fix that link Jean-Marie! Too many http's at the start.