Can't type without having letters skip or repeat, runs very slow.
I'm surprised I can type this.
I had this problem months ago and found the answer, fixed it,
printed it off and now I can't find it.
Can anyone help?
Go to Solution.
You may have switched on an accessibility feature called FilterKeys by keeping the Shift key pressed for too long.
Try Firefox Safe Mode to see if the problem goes away. Safe Mode is a troubleshooting mode, which disables most add-ons.
(If you're not using it, switch to the Default theme.)
Once you get the pop-up, just select "'Start in Safe Mode"
If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, and you need to figure out which one. Please follow the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article for that.
To exit the Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.
When you figure out what's causing your issues, please let us know. It might help other users who have the same problem.