All folders and files seems to be fine, I have some diferent themes, but I cannot use diferent Themes for diferent Albums or the Gallery when it seems it is possible... is there any reason that I ignore?

Give us a little help here.

What do you do to try to use different themes?

What occurs when you do that.

Thanks for the reply.
I´m using ZenPhoto version 1.3.1.2, starting with the Default Theme I have made my own changes to show diferent Background images in the diferent Albums and in the Gallery and to locate in diferent places the thumbnails of my images. I am making small changes only on the .css Styles files.
So, in the version 1.3.1.2, there are two ways to assign the theme for the Albums and the Gallery, one way is in each Album settings page and the other way is in the Themes page switching the diferent themes for each Album and the Gallery.
I have done both ways but it doesnt work yet.

No, there is only one way to assign a theme to an album (only top level albums!) and that is on each top level albums edit pages. On the themes page you can only show the assigned theme to any album, not assign it.

Actually, you can assign an album theme on the theme tab. But still you have not told us what happens, only that it does not work. Since you can probably assume it works for us there is not much help we can provide without your details.

Thanks for the replies.
@acrylian---In my Zenphoto version you can do that, you can switch diferent themes to Albums and Gallery.
@sbillard---It works with not changed themes, I only wanted to change a bit the styles, giving my page a background image and changing fonts, sizes... ... only in the styles file, in CSS is very simple.
I think I have found where was the problem.
We can choose diferent Themes... but may be is not possible to choose diferent Theme Colors.
So I have given the same name to diferent Theme Styles Files in diferent folders, and at this moment it works. Probably ZP was looking for the same Name in diferent Folders, I know it is a weird and confusing solution for me, working with diferent archives with the same name, but for the moment it works...

Yes, my mistake. I almost never use that feature at all (if I do sites I code that on the page directly mostly) and that way just escaped me.

To the other issue I sadly can't say anything.

Yes, there is no means to specify individually the album in the options handler for the themes. Perhaps that would be a good enhancement.