The system is working again, all votes has been reset to 0, so you can all vote again.
I made a short how-to video:
You can now vote 1 time per IP adress, so no multiple voting system anymore. This means that you can vote 1 time with any computer in your home that is connected to the internet, 1 time with your mobile phone that is connected to the 3G/4G network, etc.