Re:Install 1.7.1.1 error
Go to the URL ../tiki-admin_modules.php and see if you the 'application menu' is listed under Assigned modules. With a fresh install and as user 'admin' you should normally see the main menu.
Also if you running your Tiki on a public webserver do not leave all your files in mode 777; it's potentially dangerous. It's OK for testing etc but change them afterwards.
Regards,
Pat.