[smirkley]

admincp --> maintenance --> view php info

What do these two variables state?
post_max_size ?
upload_max_filesize ?

You will most likely have to change those variables to a higher number ie
post_max_size 15M
upload_max_filesize 15M

Then HUP/Restart apache.

If you dont have root access to restart apache, you can try using a local php.ini file with this in it, thats if your host allows local php.ini override by clients, upload php.ini to your public_html/root folder.

post_max_size=15M
upload_max_filesize=15M

As well you host may allow php_flag in a htaccess file.
edit .htaccess and add the following to it.
php_flag post_max_size 15M
php_flag upload_max_filesize 15M

courtesy of snakes1100