checklink: www.1a-geschenkidee.com

Hello

I wanted check the links of the following domain:
http://www.1a-geschenkidee.com
But I only get an Error: 406 Not Acceptable

I checked the page in your validator and got as resutl: Passed validation
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.1a-geschenkidee.com%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

Do you have an idea why I get the error 406 in the link checker?

Best regards,
Andreas