Try turning off anything having to do with auto-moving the mouse. Does your system have a touch pad? Sometimes my pad acts like I touched something when I did not. So I disabled the pad.

Whether I have the "Snap-to" feature enabled or not in my mouse software, any dialogue box opening in FF results in the mouse cursor immediately jumping to the extreme top of the screen directly above the word History. Happens 100% of the time and only in FF. Touch pad is disabled but it also happens if no mouse is connected and the Touch Pad is active (only active if no mouse plugged in). All this started around vers. 25 of FF.

Best example: When X'ing out of FF, dialogue box comes up asking to Save and Quit, Quit, Save and Restore at Startup, Cancel. Upon opening this dialogue box, mouse pointer jumps to top of screen as described above. See screen image attached.

Very, very annoying.

Clear the Cache Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

and

Remove Cookies Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

If there is still a problem, Start Firefox in Safe Mode While you are in safe mode; Firefox Options > Advanced > General. Look for and turn off Use Hardware Acceleration.

@FredMcD. Thanks. Tried your suggestions but did not solve problem. Also I have FF set to clear history and cookies when it closes. I also run Ccleaner everyday y before shutting down my system. Should I submit a big report on Bugzilla? Thanks.

Run several of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!

You may have switched on caret browsing.

• http://kb.mozillazine.org/accessibility.browsewithcaret

You can toggle caret browsing on/off by pressing F7 (Mac: fn + F7).

• Tools > Options > Advanced > General > Accessibility: [ ] "Always use the cursor keys to navigate within pages"

Note that this is an accessibility feature of Firefox.

• http://kb.mozillazine.org/Scrolling_with_arrow_keys_no_longer_works
• http://kb.mozillazine.org/Accessibility_features_of_Firefox

@FredMcD. Thanks. Have run deep scans on both MS Security Essentials, Malwarebytes, and regular scans on Spybot which I do weekly or whenever I suspect a problem. No hits, no help.

Also noticed when I am in FF Options, the response to choices is very slow. But response to clicks is fine when in normal browsing mode. Weird.

BTW, on Vers. 27 of FF, running Win 7 fully up to date.

@cor-el. Thanks but didn't help. Tried both ways. Problem persists even when I press F7. When dialogue box opens cursor shoots to the top of the screen no matter what setting I choose..

Does it still happen in Safe Mode? Did you turn off Use Hardware Acceleration?

Okay lets try this. Firefox > Add-ons > Plugins. Go thru and disable EVERYTHING. Then restart.

Hi FredMcD. Hardware Acceleration is off. When I start FF in Safe Mode the dialogue box that first appears asking to start in safe mode - the mouse pointer snaps to the correct dialogue choice. Unfortunately in Safe Mode, it is hard to generate a pop up dialogue box to test further.

Did you mean disable Plugins or Extensions?

Of interest, when I first start FF and then immediately X out, the cursor sometimes snaps to the correct dialogue choice. If I cancel then try it again, the cursor reverts back to snapping to the top of the screen.

Firefox > Add-ons > Plugins. Go thru and disable EVERYTHING by selecting Never Activate using the button on the far right. Then restart.

Hi FredMcD.

Firefox > Add-ons > Plugins. Go thru and disable EVERYTHING by selecting Never Activate using the button on the far right. Then restart.

Did as requested. No change.

Thanks.

Okay, we have just about exhausted everything to do with Firefox. Let's try this. Windows > Start > search bar > msconfig. Select Startup. Go thru the list and, using notepad, write down anything that you don't know. If you want, uncheck those entries. Once you are done select OK if you made changes (the computer will reboot) or Cancel. Then post the list here.

Hi FredMcD. Problem found! I check my msconfig on a regular basis to make sure nothing sneaks in. Image of mine below. While I have been using KeyScrambler (KS) for a few years I do recall a problem awhile back with it in another app. So I exited KS in the task bar and the cursor function in FF was as it should be - snapping to the default choice box. Restarted KS and the problem came back.

I will notify QFX Software, who produce KS, of the problem. Thanks for your persistence and help.

Great News! Good going. For the time being you may want to disable KeyScrambler. You can always turn it on when you need it.