Can't add a graphic under an existing graph hierarchy

[mvlaran]

I am currently running Red Hat 7.3 / Apache 1.3.23 / PHP 4.1.2 / MySQL 3.23.49, and everytime I try to add a graph under a graph herarchy, it simply does not include and returns to the Graph Hierarchy Item Configuration page. The same problem occurs when I try to add a heading. I just click on save and it seems to reload the page, and no action is performed in order to add the item.

Does anyone knows how to solve this problem ?