Can't remove Pragma header

Having some content caching issues with a client and I'd like to remove the Pragma header in the event that it's messing things up. I have tried the following:

 

 

when HTTP_RESPONSE {

 

log local0. "BEFORE HEADER: Pragma: [HTTP::header Pragma]"

 

HTTP::header remove "Pragma"

 

log local0. "AFTER HEADER: Pragma: [HTTP::header Pragma]"

 

}

 

 

But this always ends up with "Pragma: no-cache"

 

 

Jan 6 14:14:07 tmm tmm[2083]: Rule pragma_test : BEFORE HEADER: Pragma: no-cache

 

Jan 6 14:14:07 tmm tmm[2083]: Rule pragma_test : AFTER HEADER: Pragma: no-cache

 

 

Replacing the Pragma header works:

 

 

when HTTP_RESPONSE {

 

log local0. "BEFORE HEADER: Pragma: [HTTP::header Pragma]"

 

HTTP::header replace "Pragma" "foo"

 

log local0. "AFTER HEADER: Pragma: [HTTP::header Pragma]"

 

}

 

 

Ends up with "Pragma: foo" in the Response Headers.

 

 

Jan 6 14:28:10 tmm tmm[2083]: Rule pragma_test : BEFORE HEADER: Pragma: no-cache

 

Jan 6 14:28:10 tmm tmm[2083]: Rule pragma_test : AFTER HEADER: Pragma: foo

 

 

Any ideas?