I also still have problems. Upgraded to 2.0.7 and also just installed the latest beta.
http://ustafeltennis.nl/index.php/nggallery/2013?page_id=46/
Warning: preg_match() [function.preg-match]: Compilation failed: unrecognized character after (?< at offset 21 in /var/www/vhosts/ustafeltennis.nl/httpdocs/wp/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/router/mixin.url_manipulation.php on line 154
PHP Version : 5.3.10
