I clicked on the object and did "who am I " with debug enabler to find the name "Sims3.store.objects.moviescreen"

Then I tried

City hall>Nraas>Returner>Settings>general>by tunable xml>sims3.store.objects>moviescreen>kmoviedurationinmintes

I changed it to 3600 instead of the default and the movie still only lasted a few seconds. I want it to last an hour.

Did you set the value before starting the movie? If so, have you tried replacing the movie screen?

I've never been able to get that store item to behave itself or recognize tuning values over 1440 or something like that, and when it does recognize a new value I believe it's interpreting it as seconds rather than minutes. If anyone else has the secret to making it work properly, I'd like to know what it is as well!

Since the movies only last a few seconds (or sim minutes when tuned), my existing theaters have been taken over by sims in need of entertainment amusing themselves in more "adult" ways. You know, like drinking coffee beverages from the baristas I placed in the lobby...yeah, that's what I meant. The glowing pink mood lights are just for show and the free cinnamon and trays of romantic drinks also in the lobby are just a nice amenities (meaning after a while I got bored trying to fix the screens properly).