Hi,
I don’t know what to do of the Default Webpage, as I’d need to know what you were trying to access to see how you could get there. I find it unlikely that has anything to do with not updating, though, it would be the other way around if it’s the first time you see the screen.
About the wp-login.php, possibly when you cleared the cache you reset the passwords/users info that was entered in the first place. Just enter the login and password again and you should be set.
Cheers.
