>>> My Info: Win7_64, Nightly 49, 32bit, ID 20160526082509 STR_1: 1. Open http://www.flabell.com/flash/Simple-Flash-Mp3-Player-37 2. Open devtools -> netmonitor, reload the page 3. Open devtools -> options, enable "Disable HTTP Cache" 4. Open devtools -> netmonitor, reload the page AR: Step 4 - netmonitor shows 2 "cached" entries: "settings.xml" and "song.mp3" ER: Netmonitor shouldn't show "cached" entries while "Disable HTTP Cache" is enabled Note: If you are going to create testcase, read this: The flash player takes "pathToFiles", then adds "xmlPath" or "songURL" to it, and then grabs those 2 files. All you need is basically make it use another files (not hosted on http://www.flabell.com/) - Save the page as "Web Page, complete" - In the saved .htm file: Replace "pathToFiles=/files/" with "pathToFiles=http://www.flabell.com/files/". Replace "function initProduct(){" with "function initProduct(){return;". (Save the changes) [this is only required to make sure everything still works: click "play" button in flash player] - Upload the same .mp3 file and .xml file to the internet, and make the flash player use those files (try to upload original files to this bug, replace values of "pathToFiles", "xmlPath" to the actual IDs of attachments and value of "pathToFiles" to "https://bugzilla.mozilla.org/attachment.cgi?id=")

I'm seeing this as well. It seems like XHR requests don't respect this setting. I can confirm that it is indeed using a cached version, so it's not a display issue. Hence component is wrong and should be some more core developer tools component.