Same problem.. mysql.timeout is set to 300 in my.cnf, post_max_size = 80M, upload_max_filesize = 80M, mysql.connect_timeout = -1 in php.ini, but..
I can upload only one movie, no matter of his extension or size.
Screenshot here: http://www.elevated.ro/untitled.JPG

I`ve reinstalled many times, on different servers with different distros, but nothing. Now i use CentOS 4.4.

Any help is appreciated, i`m running out of ideas.
Thanks!