missing content / $page_name error

[m8r-lhgra4]

Need help please.

 

After updating to 1.6.0.8, all my pages display page not found for the main content. Header, sidebar, footer are displaying correctly. Only the the main content is missing and displaying page not found.

 

Apparently my $page_name is always showing 'cms' instead of the actual page name > index,...etc.

 

I suppose this is due to friendly url. When friendly url is disabled, it works fine, but once it's enabled, the problem occurs. I have removed cleanurl module, clear and disabled cache, disabled overrides, delete htaccess, disabled and enabled friendly url, however the problem is still present. 

 

I have turned on dev mode, but no error is showing.

 

Any help is much appreciated, thanks.