Lpc2000

I can't make this thing work at all!!! Serial interface works fine, 
because I tested it using Hiperterminal (I'm using a MAX202, 5V, but 
I'm sure LPC is 5v tolerant). P0.14 and RESET pins go low, after a 
while reset goes high and after that P0.14, the way it should be, I 
think. I receive a data through the serial but the board doesn't 
respond. I'm using the Philips Flash Utility V2.2.1 and it works fine 
in my MCB2100 board. There is something I am doing wrong? I'm using a 
MOSFET transistor instead of BC850 used in MCB2100, but I don't think 
it's a problem because the high e low levels are just fine.