startup window not small in tray

If I startup windows xp pro then - it happens since several weeks - the firewall window stay big and does not disappear in the system tray. I have to do this manually. How can I repair this?

Do you want to see the firewall screen on startup?

If not, go to Security/Advanced/Miscellaneous and uncheck the box, “Show application window on system startup.” Click OK and reboot.