I guess it depends on how you define "true" altruism as stated by Max. I took it to mean "unselfish." So I still maintain that there is no voluntary unselfish act. I cannot read people's minds but I can tell a lot by their actions.
Discussion
I would further define a "selfish act" as "any act that one perceives to be beneficial to one's self in any given situation."
I think "doing good because it feels good" is exactly the situation that the word "altruism" was invented for.
But we're really just talking about semantics at this point. We can agree to disagree.