Lpc2000

I'm writing the driver for the LPC2138 SSP block and I am 
encountering some strange behavior:

First of all, the user manual states SSPCR1, SSPCPSR, and SSPIMSC 
are all reset to 0x0 upon powerup.

I am finding the following values in these registers after reset:
SSPCR1 (0xE005C004): 0xF8
SSPCPSR (0xE005C010): 0x04
SSPIMSC (0xE005C014): 0x04

The processor ignores any writes of any data value to these 
locations.

Any ideas?

-Tim