need help installing my ram

hi
i need some help. my old imac died and i loved it. i bought a new one but its terrrribly slow so i bought ram. ive put ram into my macbook before and i followed the steps correctly but its not reading and its been like 3 months!! ahh!

someone on the apple.com forums was helping me but then he stopped coming on the boards and i need help and i really dont wanna pay $50 to have someone put it in for me. here's the thread where i was describing my problems and i posted pictures too.

PLEASE help if you can. thanks

heres the thread:
http://discussions.apple.com/thread.jspa?threadID=1756203&tstart=15


thank you!