Router hidden settings access

[#1]

To change the router password, change lan ip address and enable/disable or change start & end addresses for dhcp:
http://192.168.1.254/expert_user.html

[#2]

I used this link to change my router password. The new password was accepted. But now when I try to log in to the router, I'm not asked to log in at all - it is automatically logged in. This means the security is very weak. Can anyone advise - this is quite worrying.
(FYI I have tried to log in from two devices and in both case no request for a password appears now!)
thanks loads