What's the difference between F5 and Ctrl-F5 in Firefox related to JavaScript events?

When you try this public page: http://slim.nl/shop/default.aspx (update: meanwhile this site has changed such that this question's behavior cannot be tested anymore there), you'll notice a menubar. If you hit F5, the menu in that bar disappears. Same 开发者_运维百科when you come to that page via the Back-button in your browser. It only happens on Firefox (seen on versions 3-7). Using Ctrl-F5, the menubar reappears.

To the best of my knowledge, all JavaScript events that fire when loading a page, including any AJAX cycles, should also fire when refreshing a page with F5 or coming there via the Back-button. What's happening here?

I'd like to know from a programmer's standpoint what the difference is between F5 and Ctrl-F5, preferably more general than just this case. Unless it's a bug in Firefox, of course.

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Ctrl+F5 clears the cached files in browsers where as F5 just refreshes the page but it uses cached files. Eg say you load a page make changes to a css file and upload it press refresh or F5. Page just refreshes and doesn't fetch the new revised css file hit ctrl+F5 it goes it clears the cache for the page and fetches the file again from the server. This would then load the new css file which would display the changes.

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Firefox caches not only loaded files but changes made to page( user input and even changes to attributes made by JavaScript). Check this. So if your menu depends on some attributes you can just hard-refresh by clicking CTRL+F5.

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ctrl+F5 will just force the cache to be ignored. Perhaps you have a subtle asynchronous-programming bug that is only surfaces when you have a faster page load (due to using the cache).

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That issue was fixed by rolling-back \js\dnn.controls.dnnmenu.js file to previous version. Not sure what was wrong there(didn't have time to debug), but anyway now it works:)