Why can't I spoof to another MAC address?

I'm connecting to the Internet thru an wireless access point(D-Link
DI-614+) from my laptop with Orinoco gold PCMCIA card running Red Hat
7.1 [kernel 2.4.20-19.7]. I tried spoofing my wireless card to a
different MAC address before connecting to this access point with this
commands in sequence:
~$ ifdown eth0
~$ ifconfig eth0 hw ether 00:02:00:00:00:00' then
~$ ifup eth0
I can connect right away but after doing 'iconfig' it's still showing my
real MAC address and even in the access point's DHCP client list has my
real MAC address?