Access violation writing SSP0 registers

When I set up a simple project for the LPC1759,
access to one SSP0 Serial Port register generates
an access violation (Error 65) at address 0x00000020,
when the LPC_SSP0->ICR register is written. All the
other registers appear to function.
In the following code, when I run the simulator, the
LPC_SSP0->CR1 register write works correctly, writing
to address 0x40088004, but the following write to
LPC_SSP0->ICR, address 0x40088020, generates the
access write fault to memory address 0x00000020.
The write to 0x40088020 works correctly, and the
simulated peripheral behaves normally. I can map
address 0x00000020-0x00000023 as read/write and
supress the error, but is this a bug in the Keil
peripheral simulation? Here is the entire code:
The project is set up as an LPC1759.

#include <lpc17xx.h>
int main(void)
{

//This access works normally

LPC_SSP0->CR1 = 0;

//This generates Error 65

LPC_SSP0->ICR = 0;

return 0;

}
void SystemInit(void){}