Session management seems to be writing the /tmp/sess_[md5] file quite inconsistantly.  Sometime it creates a blank file, sometimes it write the file the first time, and never writes it again.

Two object instances are being stored.  session_register() is called for each immediately before it's existance is checked by the script.  

It may be worthwhile to note that the session cookie is renamed before session_start() is called, and all calls to session functions are made from within other functions.

PHP4-RC2 is build with: 
./configure --host="i686-pc-linux-gnu" \ 
--with-mysql=/usr/local \ 
--with-apache=$APSRCDIR \ 
--enable-track-vars \ 
--enable-sysvshm \ 
--enable-sysvsem \ 
--enable-debugger \ 
--disable-short-tags; 

Apache 1.3.12 is built with: 
--activate-module=src/modules/php4/libphp4.a