I've been in the back several times today, and under the keyboard in the front, didn't notice any dust to speak of. As for when it was cleaned on the inside, I don't know if she ever has, but I get the impression she's almost never used this computer so probably not often. Not sure how she stores it, but it looks pretty clean on the outside as well.
Note: I've now tried verified working ram from another computer with all the same results.
Edited by thornhillfarm, 05 March 2011 - 10:52 AM.