[TYPO3-english] Admin Tools | Install | All Configuration - Fails to update localconf.php

[Denny Fox]

Hello,

I hope someone can help me fix this.

Admin Tools | Install | Basic Configuration works fine, the changes are
writtem to localconf.php.

When I make changes in All Configuration, and click the "Write to
localconf.php" button at the bottom, I get loggged out of the Install Tool,
and the changes are not made.

This happens in 4.3.3, 4.4.0, and the 4.4.0 Introduction site. All the
Database Analysers check fine. 

This server has run many versions of typo3 4.2 without having this issue.
The current installed version, 4.2.12, Admin Tools | Install | All
Configuration works correctly. Changes are made as expected.

All the versions mentioned are installed concurrently, the environment is:

Apache/2.2.3 (Debian Etch) DAV/2
PHP/5.2.0-8+etch16 
mod_ssl/2.2.3 
OpenSSL/0.9.8c

I have searched the net and email list archives, what am I missing?

Many thanks,

Denny Fox