I found (maybe) a right way to make correct query.
At first I query "whois.iana.org" for 1st level domain name. From result I grab whois server or if not here then I set server to undef. At second I query appropriate whois server. For '.nl' domains is used special request because some restrict here ;-(
Example:
$whois = Net::XWhois->new();
my $domain = 'sex.com';
my $top = $domain;...
2007-05-13 17:00:38 UTC in Net::XWhois
