Session question...

Hello everyone-- I'm running PHP4 and using it's session functions and here's the problem I'm running into. On my logon page I use the session_start() function to create a new session and then i use the session_register() function to hold all my user information. The problem I am having is that when I go from page1.php to page2.php it is creating a new session id for me. For example: page1.php: session_start(); //gives user an SID //register variables etc... and submit via form //which goes to page2.php page2.php: session_start(); //register variables etc... and encode/decode to //retrive all the session variables I need. The problem is that say on page1.php i get an SID of xxxxxxxxxxxx... and then when it goes to page2.php it sets the SID to yyyyyyyyyyy... for some reason. My session maxlife is set to 1440 so I don't have a clue as to why my session id is getting changed at every page i go to. Any suggestion? Thanks, Jay Paulson