Hi,
I'm writing this post on behalf of a person who asked me to help him with this.
His website is not exactly fast, but that may depend on the fact that he has a lot of albums and he's on a shared hosting; the problem anyway is with the control panel.
If I login in there I can browse it without problems, except that the Upload tab and any album managing page won't load, thing that doesn't let me upload new albums/images through the web interface or edit albums and images details.
Simply, the page open but it loads only the tab menu, not loading the rest of the page where I can actually do some operations.
I don't know how to debug this, can anyone help?

There are numerous shared hosts and they don't necessarily need to be slow.

The first thing you need to look into the server error log. Also read this topic as that might be related: http://www.zenphoto.org/support/topic.php?id=10369

Thanks, let's see in darkufo can help me, the problem seems to be the same.