A lot of this is easily fixable. It looks like I'm having a pop at Cineworld but all the chains of cinemas are as bad as each other.
Cineworld have leaflets of showtimes. Each one is specific to the venue as it has the map of how to get to it. Considering you can only pick them up in the venue I'm guessing they worked that out already.

Anyhow, why can't they put on that a list of forthcoming films that will not be shown at that venue. That way people know to look at other branches or if need be a different company.
That will save people holding on for the film on the off chance it opens later than elsewhere as has happened with Four Lion which got a few screenings last week and is now gone.
A full listing of films and venues being shown could be put in the magazine.
Every cinema chain's website could post in advance where a film is or isn't going to be shown. They know further than just 2 weeks ahead where films are going to be shown, so why not do that? The Odeon website are selling tickets for Twilight that opens in July. So that shows they know what film and the times are on that week well in advance.
Tooth Fairy s due to open on Friday. The Odeon, Vue and Cineworld have any details of that on their website at the moment as being shown in any of their cinemas. Does that mean it's completely cancelled?
The Vue are listing the Thomas the Tank Engine film opening months away in a whole host of venues but strangely not Greenwich (the O2) for some reason. Why that is the only film they are promoting so far in advance when they aren't doing it for Potter or Narnia I have no idea.
The point is I now know well in advance if I want to see that film don't bother waiting for it to go to the O2 venue because it's not happening. Why can't all three of their websites do something similar for all the films? It would be useful to know that I don't need to go and see a film at a different one of their cinemas in the first week of August when it's opening in my local one in the fourth week in August.
This doesn't help with each venue showing all the main films at least once or twice but it does help me to know I need to look elsewhere.
As I said easily fixable. Start a policy of clearing all the screens of the current listings one or two days every fortnight and show all the films on a set day (make it the day when that venue takes the least money) as an single showing day. And better promotion which films are and will be showing at which cinema and when well in advance not just a week or two.
If you fancy seeing the film The Losers due to open Friday give up, as according to all of their websites, like Tooth Fairy they aren't showing it anywhere in the country, or {Rec]2 or Space Chimps 2 either.
Apparently the only film opening in the country this week is Sex in the City 2.
I think it's safe to say all their promotion departments suck.
Support the film industry. Why? They obviously don't care enough to even try.