Try this:
AuthType Basic
AuthName "Authentication Required"
AuthGroupFile /dev/null
AuthUserFile /home/alltest/public_html/.htpasswd
require valid-user
This keeps the password in the browser cache until you exit the browser. I fit's possible, I suggest keeping the .htpasswd file out of the public directory.
If you're using cPanel, there could be something in the config files of the web server...