This came out ages ago here too. I've heard that it's apparently had huge problems getting distribution in the U.S. thanks to the gay content - or at least, gay content in a comedy with two big stars.
weirdly problematic.
That's exactly the way to put it. When I first watched the trailer, I had similar expectation to the people in the cinema you're talking about: I was expecting (probably because of the star power involved) that the gay 'angle' was going to be the POINT in some way - that one of the characters was going to be pretending, etc. As I slowly realised that this wasn't the case I was pleasantly surprised.
To an extent the film itself bears out this desire not to make the homosexuality an ISSUE - which is great. However, in a sense it makes itself "problematic" by trying to make this point too strongly - by almost going out of its way to say "we're totally cool about this". I'm thinking particularly of the way it reveals Carey's sexuality, and a couple of sexually explicit jokes made along the way that I just think would not be in the movie if it was about a straight couple. And the way it handles a potentially melodramatic plot towards its end.
Still, it's an interesting - if not great - film precisely for these reasons, as well as for a few others. Regardless of problems, this definitely is a step forward in terms of depicting gayness in something approaching mainstream film. I just look forward to the time when it becomes so normal that movies can avoid some of the awkwardness that this film still contains. And also to when movies like this can be made and distributed like a regular film by a major studio.