Gary Kuhlmann - August 27, 2012
Recently I was asked to increase the upload limit of a WordPress installation that I am hosting. I knew that the limit was based on the setting inside my php.ini file so I opened the file and changed the upload_max_filesize variable setting to 50M. That should do it, right? Not really. I then logged back into the WordPress install to find that my new limit was 8M. This was four times larger than before but still not good enough. Alright, lets Google it. After some searching I found that there would actually need to be four variables (one modified, and three added) used to make this change.
post_max_size = 50M upload_max_filesize = 50M max_execution_time = 900 memory_limit = 30M
This took care of the issue and now the user can upload his large files!Source: http://wordpress.org/support/topic/nextgen-gallery-how-to-change-php-upload-limit