i know why this.

if set [color=#FF0000]server_name *.abc.com;[/color]

and set
[color=#FF0000]
location ~.*\.(gif|jpg|jpeg|png|bmp|swf)$ {
valid_referers none blocked server_names *.abc.com *.google.com;
if ($invalid_referer) { return 403; }
}
[/color]

it will be "[emerg]: conflicting parameter "*.abc.com""

i del *.abc.com from valid_referers no problem.

thank you Dave Cheney

bug?