Isn't this almost like the subject of morality? I mean that truth and lies are based on opinion, like morals, and they differ from person to person. We all know the saying "Opinions are like assholes: everyone has one", and this seems to play into this issue quite a bit.
Lets say that I was told that it was ok for me to judge people based on the color of their skin or their sexuality for my entire life. To take it further, let's say that my entire life I was told that these people were inferrior to me because I am a straight white male. Well if someone came along and told me different, I would call them a liar, and would have the right to believe that wholeheartedly.
I agree that all lies are wrong, even if it is a small lie to console somebody. If you lie to that person to make them feel better, someone else is going to come along and tell them the truth and make you look like a jerk. Aside from that, it gives people false security and when they find out that everyone has been lying to them, it could cause some sort of complex.