phpMyAdmin configuration
How to set phpMyAdmin default 1440 second timeout higher:
locate php.ini
el@apollo:/var/lib/phpmyadmin$ locate php.ini /etc/php5/apache2/php.ini
open the file as root to edit, find this line:
session.gc_maxlifetime = 1440
Change it to this (500000 seconds is 5.7 days)
session.gc_maxlifetime = 500000
Restart apache.
Doing this decreases security because then it increases opportunity for cross site scripting and man in the middle attacks. It's all fun and games until you find your server is part of a botnet farming for credit cards.
config.inc.php > $cfg['LoginCookieValidity'] = 3600 * 9; // 9 hours
edit from the link posted by ajreal: LoginCookieValidity
for the second question , after changing upload_max_filesize in php.ini did you restart apache ( or whatever webserver you use ) ?