Hi Antonin (@elwood4717), thanks for getting back. Please kindly send the diagnostic data to one of our support representatives @ http://www.tobii.com/tech/contact/ who should be able to provide further troubleshooting feedback.
In the meantime, it might be worth deactivating any firewall or antivirus software that may be blocking the tracker connection. In addition, if you can test on another PC that would be a good idea.