I am using WP 3.5.2, PHP 5.4.16 and MySQL 5.5.28. mod_rewrite is activated and safe_mode off.
My permalink structure is /%year%/%monthnum%/%day%/%postname%/
With NextGen Gallery 1.9.13 everything was fine, but after upgrading to 2.0 all links to individual posts (http://<my-server>/<yyyy>/<mm>/<dd>/<postname>) display the main page.
Manually changing the URL in the browser to http://<my-server>/index.php/<yyyy>/<mm>/<dd>/<postname> displays the correct post.
I have disabled all other plugins to verify this is caused by NextGen Gallery.