.htaccess protection / php

hi, i have written a php script, that automatically creates an user directory, a .htaccess and an index.php file in this user dir. the file, where the username and the password is stored, will also be created automatically. now the problem: i am using the php " md5( ) " function to encrypt the password. so, when i want to access to the new user "index.php" the password pop-up window appears and i type in the username and password, but i can´t access the user file. can someone tell me what´s the problem?? why doesn´t it work?? thanx for help greetz andreas