You get an alert about resending POST data if you go back to a page or refresh a page that was previously requested from the server by submitting form data via a (hidden) POST form.
Firefox can only make sure to get the same page by resending that POST form.
Firefox doesn't know what that form data means, so Firefox asks for confirmation before resending that form data as such an action can cause you to repeat an action and buy another item or post a message another time.
A way to prevent that pop-up is not to use the Back button, but to open links from a page that was requested from a server by sending a POST form in a new tab (window) with a middle-click or a Ctrl + left-click.
Then you can close that tab or window to go back.

its not the back button, it does it all the time when you want to send any info keeps asking you this same question

No, cor-el....that is not the answer....the stupid little box is stopping anything running sripts or real time....which means weather radar....you tube videos, GMT time screen...anything that refreshes by a script is now not function once the little ox decides to show up. It started doing this spontaneously 48 hours ago...totally wrecking the way I use internet. Mozilla pushed out a change without my permission because I have "do not install updates without asking" set up. A) What do i do to get the annoying blue box to stop and B) how do i prevent anything else from being changed without my permission

It shows up on anything that needs to be refreshed. Somehow we all got an update without permission. Anyone care to tell me how to fix it?

@blueecb:

An alert about script that does not respond is a different issue and is not the one that is the subject of this thread.

See:

• http://kb.mozillazine.org/Unresponsive Script Warning

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See:

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

I'm referring to the "To display this page, Firefox must send information that will repeat any action " it continually displays upon any attempt to refresh. That being said is their anyway to fix THAT issue lol?

To display this page, Firefox must send information that will repeat any action (such as a search or order confirmation) that was performed earlier. This messaged moments ago while in safe mode. The problem definitely belongs to Firefox, not any scripts.

Thanks for the help everyone but I have tried safe mode, disabling addons, etc, it does not fix the problem..

Is there any way to disable this popup in the about:config?