Google captcha problem on newly rented subnet

We'rehaving some problems with a newly rented /24 subnet in context with Google.Google always asksfor entering a captcha code three times in a row.The reason for thatcan't be a misconfiguration of the server, because we have more than 40different servers all around the world configured exactly the same way where this problem doesn't appear. It could be due to the history of the subnet.  Can any representativeof Google please contact us via E-Mail, in order to tell him/her which subnetis affected by the problems and solve the issue by removing those permanent queries? Anders Philip Temsvåg