Does nobody has an idea? or maybe a idea where i can look for more info?
You have a couple of options:
1- Check an open source library called socialauth, You would use an authenticator that delegates to socialauth and extends seam authenticator.
2- Seam 3 has some example for openId, check the example folders for Seam3 release.
Can you paste the URL that's being sent to Google? The error message that you're getting indicates that one or more of the parameters is incorrect.