I'm running on <a href="http://www.mediatemple.net/#a_aid=4eeb8332c44fa">Media Temple's</a> DV Managed server. Out of the box I had problems uploading files larger then 16MB on WordPress. Turns out to be an issue with the way Plesk hands out the settings to the domains.
Find the line with 'FcgidMaxRequestLen'. The number is in bytes. To increase the 16MB to 1GB set
the FcgidMaxRequestLen to 1073741824.
Then configure to apply the settings to all your websites run the following: