Hello, I can't modify header.php nor any .php files via the edit command.

I got the message: Warning: Cannot modify header information - headers already sent by (output started at /home/rousset/public_html/zenphoto/zp-core/admin-functions.php:78) in /home/rousset/public_html/zenphoto/zp-core/admin-functions.php on line 3466

Plus, I can't modify the gallery description in options>gallery (justify text and so on). All is locked. If it's a chmod issue, I don't know what to do. They are 755, and my host doesn't allow relaxed permissions. He says that the way they setup permissions, 755 works like 777. Hard to believe...But maybe it's not that?

Thank you!

None of the official themes have a header.php file. You really should provide at least the basic info (see the forum rules for example). Of course I know by now that you have issues with zpFocus. So I really suggest to put that into the topic headline so its developer might be able to spot your questions.

Anyway, the header warning you get has nothing to do with any header.php file but with the internal header info sent with every pages. This is a php issue as you probably added something where you shouldn't (what I don't know as I don't know htis theme.).

Thank you for your answer.
It's the zp-galleriffic theme I am talking about.
I am not sure the fact that I can't work on php files is related to the 3rd party, since I was able to do so before I changed my host. For example, now, when I try to copy one of the official themes, in order to customized it, it doesn't work. I get this message: "theme" Cross Site Request Forgery blocked."
And do you think the fact I can't justify the gallery description and use the buttons of this window is related to the 3rd party theme?

Ok, zpGallerific is also a 3rd party theme I am not familiar with. It is heavily Javascript powered which might override TinyMCe settings. Its developer will know.

Regarding the Cross site request forgery: That is not related to file/folder permissions. If you are not on 1.3.1.2 you should upgrade as the 1.3.1.x releases are also bugfix releases to that security enhancment.

Thanks, I will upgrade to the 1.3.1.2