nginx ignores proxy_ignore_headers

[VRider]

I am running nginx 0.8.54 on CentOS 5.2,
In nginx.conf I have set 
proxy_ignore_headers Expires Cache-Control X-Accel-Expires;

but still I get bunch of misses because of expire date.
For example:
***22/Feb/2011:21:31:39 +0100 MISS Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /opensearch HTTP/1.1" (200)
***22/Feb/2011:21:31:40 +0100 MISS Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /opensearch HTTP/1.1" (200)
***22/Feb/2011:21:31:43 +0100 MISS Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /opensearch HTTP/1.1" (200)
***22/Feb/2011:21:31:47 +0100 MISS Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /opensearch HTTP/1.1" (200)

Similarly:
***22/Feb/2011:21:33:52 +0100 EXPIRED Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /xxxxx/xxxxx HTTP/1.1" (200)
***22/Feb/2011:21:33:52 +0100 EXPIRED Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /xxxxx/xxxxx HTTP/1.1" (200)
***22/Feb/2011:21:33:53 +0100 EXPIRED Cache-Control: no-store, no-cache,
must-revalidate, post-check=0, pre-check=0 Expires: Thu, 19 Nov 1981
08:52:00 GMT "GET /xxxxx/xxxxx HTTP/1.1" (200)

Any idea why that happens?

D

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,177542,177542#msg-177542