Version:           inconnu (using KDE 3.2.0 RC1, compiled sources)
Compiler:          gcc version 3.3.1 (Mandrake Linux 9.2 3.3.1-2mdk)
OS:          Linux (i686) release 2.4.22-10mdk

When the mouse hovers an element, the name is always in english in the tooltip.
It seems the problem is in the mechanism for displaying i18n, because all strings in the source file are i18n.

In the infobox, the title bar shows the translated name of the element, but in the title of the box, it is also in english.

Or perhaps it is a way to learn english names for the elements ? ;-)

The only place where you find "Iron" for example in the source is

kalzium/src/kalziumrc

Name=Iron
Symbol=Fe
Weight=55.845
(...)

Of course, Iron is translated in po file.