I have the same thing as Tarkus. I just noticed it a little while ago. When I go to edit my profile, it is okay. Thought I was the only one. My profile shows December 31, 1969 also. I wish that really was my birthday. HeHe.
Edit; Tarkus, after looking at a lot of other profiles, it looks like you and I must be the only ones with this problem. That's really strange.