Not accessing some admin language files

[Dhananjaya]

The admin menu is showing lots the code referring to the language file instead of the text from the language file.

For example the main menu shows CATALOG_CONTENTS instead of Contents.

Some text is working some isn't.

It appears that the english.php is being accessed correctly and if I copy and past the code from the other language files into the the english.php languange file then the text pulls in okay.

I have re-uploaded all the default admin files and still no change.

I have scrutinized my configure.php and it is just like another site I have that works.

I though maybe it has something to do with my php.ini settings but they are standard except register globals is on and safe mode is off.

Anyone have any clues where I might look for clues?