Hi Babycat
In addition, please make sure you DISCONNECT the board with IDE debugger when measure.
In default demo code, you need to select option 4 on hyper terminal to enter Deep power down mode. Try to revise the code to let LPC804 automatically go into deep lower down without remote control at the beginning code the main code.
download, power off and power on, Let the board run in standalone mode ( disconnect PC debugger)
Measure current again. You should be able to see consumption current down.
Have a nice day,
Jun Zhang