在用httpfox抓包的时候，发现如标题发生的情况："Content" tab issues NS_ERROR_DOCUMENT_NOT_CACHED on all POST/GET，
查询了一下，果然在官方的issue中发现了解决方案。再对比了一下我的设置，原来，我将一些Cache都关闭了，怪不得呢。
What steps will reproduce the problem?
1. Get the Firefox 3 Nightly build (tested with Gecko/2008051006)
2. Run any POST or GET request
3.
What is the expected output?
What do you see instead?
expected the "Content" tab to display the responseXML/responseText, it displays "Error loading content (NS_ERROR_DOCUMENT_NOT_CACHED)" What version of the product are you using?
On what operating system?
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9pre) Gecko/2008051006 Minefield/3.0pre
Please provide any additional information below. hopwe this is an easy fix :)
very sad to have found it to replace bulky Firebug to find out it doesnt work :(.
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回复如下：
please check the following firefox preferences: (this can be done with the "about:config" url)
1) browser.cache.disk.enable make sure this is set to "true" (default: true)
2) browser.cache.memory.enable make sure this is set to "true" (default: true)
3) network.http.use-cache make sure this is set to "true" (default: true)
4) browser.cache.disk_cache_ssl setting this to "true" should help getting the content of https requests. it is deactivated by default for security reasons. (default: false) (see http://kb.mozillazine.org/Browser.cache.disk_cache_ssl)
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OK，问题解决。
http://code.google.com/p/httpfox/issues/detail?id=20