Lpc2000

We are working on a prototype board of our product with the LPC2105. 
When we try to flash our program, we are getting an error "can't 
communicate with test board". We have a serial cable connected to the 
Uart0 ports (pins 13, 14) through a MAX3232 converter. 

On the test board side, we have verified that the VDD3.3 and VDD1.8 
and GND are all connected correctly. RST is tied high and pin 44 
(P0.14) is tied low (to enable flash program mode). We checked to 
make sure the oscillator is operating correctly - it is. 

We, of course, have checked and rechecked that Tx and Rx are 
configured correctly from the pc to the test board.

I'm wondering if anyone has encountered any issues when programming 
the LPC that might be helpful for us to solve our dilemma? Is there 
something missing? 

Also, the other thing that we are confused about is when the flash 
programming utility gives us an error, we can't see any activity on 
either the Tx or Rx lines. We put a scope on those pins. How can it 
know whether or not it can connect to the test board, if it doesn't 
communicate to it?

Any help would be greatly appreciated.

Thanks,
Bryan