sql connexion fail with poll

I have installed pollphp and it works very well. Thanks for the author !

But when I want to include it in another php file, I have a sql connexion problem.
Warning: mysql_connect(): Access denied for user: '...@localhost' (Using password: NO)

My config file is Correct (connexion ok on the other page with only the poll on it).
The problem begin when I include it in another php file.
I read a lot of people has this problem. Nobody can help ?
Is the problem can be a multiple connection to the database ?
Any idea ?
Sorry about my bad english
Thanks for ur help !

Strange... I thought "(Using password: NO)" meant it didn't have your database user's password.