Why aren't Kyuubi and Naruto real allies? Several characters in the Naruto universe share their bodies with other entities, most of them are true allies. They share the Power both have, even if one has the upper hand controlling the body.

My question is, why doesn't this happen with Kyuubi and Naruto?

Several times Kyuubi saves Naruto with his red chakra out of hairy situations. Naruto is aware of it and sometimes they talk to each other.
Kyuubi is an evil Daemon, sure, but due to the fact tat he would die if Naruto died; and Naruto, as a Ninja, has a dangerous live; it would be in Kyuubi's advantage to help out, given that his Chakra is way stronger than Naruto's.

Why don't they team up?

EDIT: Question regarding Naruto Vanilla not Shipuuden or anything else.
If by "Naruto Vanilla" you mean the manga, then


   Naruto and the Kyuubi actually did become allies in the later parts of the manga. As it turned out, just about all the Tailed Beasts, including Kyuubi, were mistreated and abused by humans, so they distrusted and disliked humans. That's why Kyuubi wasn't that friendly to Naruto, or at least at first.