[shinta]

well from what I remember

Spoiler:

The 4th sealed the Kyuubi into Naruto not wanting everyone to hate him, but for people to see Naruto as a hero who lives with the burden of the village. After the 4th's death everyone was "tolerable" to Naruto, but as soon he wasn't remembered as much, and the 3rd couldn't keep up with the 4ths wishes, everyones parents hated Naruto. (Extremly long sentence, sorry) The 4th didn't want everyone to see Naruto as the holder of the killer of soo many konoha shinobi, but people think what they think. So in my own opinion, I think that Naruto maybe the 4th's son because he gave Naruto a huge responsibility to carry. I don't think the 4th would have done that for some strange baby.

thats what I think anyway, I could be wrong