sessions and my class...

Here is the problem I have a form --> user enters a login name the login name goes to another script for processing there a session is started and the class is registered session_start(); session_register('classname'); and actions are taken on the login name... if it is good then a variable (valid) is set to 1 in the class and the code redirects to another script.... header("Location: other_script.php4") in that script the session is checked for.... session_start(); session_register('classname'); and the code checks for the login veriable. if(!$classname->valid) { ##send to login } This keeps people from comming back to the page without logging in. what is happening is that the variable is not being found even though it is being set in the class, so the user is redirected back to the login screen... HERES THE FUN PART..... When the user enters his login name again.... the script works, the variables are set, and the class is registered. What am I doing wrong? If anyone needs to look at more of my code Ill send it, but this is all it does... is there some problem with using sessions and headers? is my PHP install Pooched? Please help. Dallas K.