Macbook Pro serial number

HI,

I have the following Macbook Pro:

A1226

2,2 GHz Intel Core 2 Duo

2 GB 667 DDR2 SDRAM

Nvidia GeForce 8600 GT 128 MB

MacBook3,1

L2 casche 4 MB

BUS Speed 800 MHz

Boot ROM MBP31.0070.B07

SMC Version: 1.16f11

1. The problem is I CANT READ MACHINE SERIAL NUMBER in "about this mac". The MAC OS doesnt want to show me the serial number of the machine. I have tried to see it within the Leopard 10.5, Snow Leopard 10.6 and finally from Lion but NO WAY to do it.
2. is it a problem with too old FW, maybe?

Can anaybody help me, please?

thanks

Robert