production company (presents)

I think they are involved in distribution rather than the actual production of the film.

Isn't it like those films listed as "Quentin Tarantino presents" where his main involvement might be as an exec producer, but he might get his production company hooked in?

Can you provide any examples you've found so we can check.

I mean, a company's page on IMDb (say Warner Bros. for example) will have a few different lists of credits, including "distributor", "production", "miscellaneous", and "special effects". If you look at the list of production company credits, after each title it will say "production company"... which seems a bit redundant, considering they're under the production list in the first place... but sometimes after the titles it will say "production company (presents)". What I don't understand is if that means they're just the distributor of the movie, why is that title even under the "production company" heading instead of just under the "distributor" heading?
http://www.imdb.com/company/co0026840...

If they were credited as distributors then they'd be listed in that category, although the role might be similar (they might, for example, have agreed to pay some of the costs to the distributor or allowed their name to be attached to a film to get it a distribution deal or they might just have twisted a few arms to get it distributed). Warner Bros, for example, have a deal with Legendary Pictures to co-produce and co-finance films with them and if you look at the films with "presents" credits (like Man of Steel or The Dark Knight Rises) you'll find they are produced by Legendary. I suspect you'll find similar deals with other companies where they get those credits. So they might also have provided money or attached their name to a film to allow it raise funds (perhaps underwriting or guaranteeing money for investors).

tl;dr: The credit is saying: These people helped get this film in front of you, perhaps by helping finance it or allow it to get financed/distributed by attaching their name to it.

Basically, if you are submitting data, you have to submit what is on the credits. So if it says "Warner Brothers presents" then it goes in the Production Company section, with the "presents" attribute. Other popular attributes in that section include "in association with" and "co-production".

A "presents" credit would tend to mean that they didn't really contribute much to the actual production. See discussion here:
http://herald-review.com/blogs/decatu...
http://answers.yahoo.com/question/ind...
http://boards.straightdope.com/sdmb/s...
http://www.chacha.com/question/what-d...
http://answers.yahoo.com/question/ind...

It is a little... vague, but it isn't IMDB's job to question the credits, just correctly store it.