In version v0.9.5 there are some changes in the Database.
After you overwrite all the .php files & directories,
surf to the console and in the 'admin' menu click on 'Create Db Tables'.
The DB will automatic be upgraded to the new version.

Goto admin menu and select 'delete all'
Then update the rules from the internet again.

You also need to upgrade the sensors to v0.1.6-RC1