Why does Nginx log same request two times?

[rayallenwu]

In my log files, every http request shows double times.

122.193.13.10 - - [27/Nov/2009:13:39:46 +0800] "GET /images/fanfou.gif HTTP/1.1" 200 149 "http://www.xxx.com" "Mozilla/4.0..."
122.193.13.10 - - [27/Nov/2009:13:39:46 +0800] "GET /images/fanfou.gif HTTP/1.1" 200 149 "http://www.xxx.com" "Mozilla/4.0..."

I'm using Nginx 0.7.63 on windows 2003. The problem doesn't occur on windows xp with the same config file and code.

So, does it mean that client sends double requests or this is just an bug of Nginx's logger module?

Thanks

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,26189,26189#msg-26189