Perform the suggestions mentioned in the following articles:

• Resetting Download Actions
• http://kb.mozillazine.org/File_types_and_download_actions#Resetting_download_actions

• Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
• Clear Cookies & Cache

Check and tell if its working.

Not related to your problem but some of your Plugins are out-dated

• Update All your Firefox Plugins -> https://www.mozilla.org/en-US/plugincheck/
• When Downloading Plugins Update setup files, Remove Checkmark from Downloading other Optional Softwares with your Plugins (e.g. Toolbars, McAfee, Google Chrome, etc.)

Didn't fix the problem, seems to be a problem with Google Instant Search and the Firefox browser.

Did you try start Firefox in -> Diagnose Firefox issues using Troubleshoot Mode to check if you can use Google with Instant Search properly while using Firefox Safe Mode ??

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

The same thing is happening in Google Chrome: http://www.google.com/support/forum/p/Chrome/thread?tid=0118990e7d5dbb33&hl=en

Must be a Google Instant Search problem. I think I'm going to disable Instant Search.

II was also annoyed by 'json" pop up window. Multiple clicks and it kept popping up. So I saved the file and later right-clicked on the "search" icon and selected PROPERTIES on my desktop (could be somewhere else on your machine). In the advanced options one can check an option to delete the "json" application. I can't be more precise than that since deleting the application brings up different advanced options. But you will surely know where to click when you see it. Power users may like this application but it is a pain in the back for normal users. Hope this helped.

See also [/questions/921535]