If were my problem it would be the mouse pad on laptop, fortunately I have a switch to turn it on or off, but I almost always use an external mouse.

Your problem might be hitting the single quote, which is Quick Find in Firefox, although I type a lot of single quotes in support supplies without the problem.

Tools > Options > Advanced > General > (I have all 3 accessibility options turned off at the top)

You can prevent the backspace key from going back in the tab history

• http://kb.mozillazine.org/browser.backspace_action (2)

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.
You can use the Filter bar at to top of the about:config page to locate a pref more easily.

Thanks, it suggests for me to change the integer value - what should it be if I want it off? Thanks!

Cor-el suggested a 2 alongside his answer -- Mozillazine is down right now you can read a Google cached copy at

• http://webcache.googleusercontent.com/search?q=cache:http%3A%2F%2Fkb.mozillazine.org%2Fbrowser.backspace_action