Whenever i try to create a new album or collection and i click create, i get redirected to this url http://gallery/admin/plog-manage.php and the page can not be found?
It appears that you have safe_mode enabled on your server. Plogger-RC1 has a built-in workaround using PHP's FTP functions to create directories, but if you were not prompted for this information during install or upgrade then Plogger cannot work on your server (it's a limitation of permissions and PHP, not Plogger itself. I don't know of any other gallery script out there that works on safe_mode enabled servers without FTP functionality). You'll either have to contact your webhost and ask them to disable safe mode or enable PHP's FTP functions OR switch webhosts if you want Plogger (or any other web-based gallery script) to work properly.
The only free webhost that I have tested Plogger on (although it was awhile ago) is http://www.freewebhostingarea.com/. It also looks like they no longer have safe_mode enabled either, so it should work either way.