LOL
I’m running 3.5.4 and it works as it should.
Is your spell check as you type enabled? Go to Edit-Preferences, click the Advanced Icon at the top and on the “General” tab, it should be at the bottom of the “Browsing” section. “Check my spelling as I type.” Make sure that is checked.
Have you got that checked?
My advice is this: Uninstall Firefox, and install Chrome instead.
If you like a really fast internet experience, you will want to switch to Chrome.
I bumped a group of keys on my keyboard, which evidently toggled on a “feature,” by which every time I hit a / or a ‘ (slash or apostrophe), a “Quicksearch” box opens at the bottom of the window.
Even after consulting Firefox’s “Help” forums, the only way to stop it was to do a System Restore. It hasn’t come back—yet.
It still happens when I’m reading a page, but not when I am typing in a data/text field, like right now.
Punt, Reboot.
Someone else on FR had the same problem that you are describing. He blamed it on Vista, but it is obviously a Firefox glitch. .
The last couple of Firefox upgrades have slowed my machine down - sometimes when opening Freerepublic, it hangs up and goes to the ask.com search page. One chat room I used to frequent kicks me completely off the web if clicked upon.