I'm using PHP 4.2.0-RC4 with Apache 2.0.35. The following   
script does not return the session_name=session_id, using 
the SID constant, as expected:   
   
<?   
   session_start();   
   echo "session id is ".SID;   
?>   
   
Configure line:   
   
./configure  --with-apxs2=/opt/apache2/bin/apxs --with-xml   
--with-openssl --with-sybase=/opt/sybase --without-mysql   
  
Session configuration is as follows: 
 
; Argument passed to save_handler.  In the case of files,  
this is the path  
; where data files are stored.  
session.save_path = /tmp  
  
; Whether to use cookies.  
session.use_cookies = 0  
  
; Name of the session (used as cookie name).  
session.name = PHPSESSID  
  
; Initialize session on request startup.  
session.auto_start = 0  
  
; Lifetime in seconds of cookie or, if 0, until browser is  
restarted.  
session.cookie_lifetime = 0  
  
; The path for which the cookie is valid.  
session.cookie_path = /  
  
; The domain for which the cookie is valid.  
session.cookie_domain =  
  
; Handler used to serialize data.  php is the standard  
serializer of PHP.  
session.serialize_handler = php  
  
; Percentual probability that the 'garbage collection'  
process is started  
; on every session initialization.  
session.gc_probability = 10  
  
; After this number of seconds, stored data will be seen  
as 'garbage' and  
; cleaned up by the garbage collection process.  
session.gc_maxlifetime = 1800  
  
; Check HTTP Referer to invalidate externally stored URLs  
containing ids.  
session.referer_check =  
  
; How many bytes to read from the file.  
session.entropy_length = 0  
 
;session.entropy_length = 16 
 
;session.entropy_file = /dev/urandom 
 
; Set to {nocache,private,public} to determine HTTP 
caching aspects. 
session.cache_limiter = nocache 
 
; Document expires after n minutes. 
session.cache_expire = 180 
 
; use transient sid support if enabled by compiling with 
--enable-trans-sid. 
session.use_trans_sid = 0