Lpc2000

> void writeToFlash()
> {
> 	command[0] = 54; 
> 	iap(command,result,0x7FFFFFF0);
> 		
> 	command[0] = 55;
> 	iap(command,result,0x7FFFFFF0);


I'd really like to see how u defined your iap function pointer.

Regardless, ensure that the IAP function pointer switches to thumb 
mode and takes 'only' 2 arguments (Command & Result).  Note that 
function pointer must go to address 0x7ffffff1 (not 0x7ffffff0). 

Look closely at the "IAP Command" section in "Flash Memory System & 
Programming" in your User Manual.

Leighton