RAM problem

it wasn't until about 3 months after i purchased my macbook i started experiencing random shut downs, vertical lines, the whole nine yards. when i first got it, i replaced the ram with 2 sticks of 512 mb from memory 10. i just called apple care to finally have them fix it (me resetting the pram isnt helping anymore) and they said i need to put in the original ram because it could be a ram problem. does this make sense considering i had it in there 3 months prior to the problems and it was fine? see the thing is..i cant find the original ram. am i out of luck? i heard apple wont even touch my computer if the original ram isnt in it. i just want them to replace the logic board since that seemed to be a number of people's problem as far as random shut downs go. help!

Edit: has anyone else experienced random shut downs because of memory 10 ram?

 

i definetely didn't sell the memory - it's around here somewhere it's just a matter of tearing my room apart...i just doubt i'll find it. in any case, if i don't find the ram can i request that they replace the logic board anyways? if my ram is the problem, is there any way for them to test with original ram that is supposed to go in the machine? i'm sure they have some laying around. the thing is, it's not an easy problem to test, i'd imagine - intermittant random shut downs. i don't know anything about the warranty that comes with the ram, i guess i'll look on the receipt. another thing i have to search for. damn.