Running Firefox 31, Windows 7:

I was running into a bug on a website that I'm testing, where some things that did exist but do not anymore, were still showing up. I tried clearing the cache by pressing Ctrl+F5, but that was not fixing the issue. I then tried clearing cookies, and that still wasn't fixing the issue.

I then tried viewing the site on a different computer — also running Firefox 31 — and the site was showing up like it should, with the old stuff that was deleted gone like it should have been. I tried clearing the cache using Ctrl+F5 on the computer that was having the issues for the 50th time, but to no avail, I was still seeing the bug.

I then tried going into the settings instead of pressing Ctrl+F5, and clearing cache that way, by deleting only the cache. This actually worked for me, and I was no longer seeing the bug.

So with that known, why was I still seeing the cache, even though I hit Ctrl+F5 many times to reload the page without the cache? The code didn't change while I was doing all of this, it just seems Ctrl+F5 wasn't working at all for me for some reason (and if I press F3 it does the find function so I know my F-keys are working).

Even the Firefox support site shows that Ctrl+F5 can be used to override the cache, but that wasn't working for me. So does Ctrl+F5 just randomly not work? What could the issue have been? It feels like I now need to go into the settings every single time I want to reload the page without cache, which is fairly often. I know there are workarounds like disabling cache completely or plugins to remove it on click, but I still want cache to show up sometimes, and if the key combination that firefox itself gives us doesn't work sometimes, who's to say a plugin made by some third party developer won't work randomly either?