Originally Posted by LTheobald
With "Find As You Type" off, this toolbar should only pop up when you press the shortcut for it - CTRL+F. Are you sure you aren't accidentally pressing that key shortcut?
If not, I would guess that you have installed an extension that is causing Firefox to do this. Have you installed any extensions? If so, tell us which ones by clicking Tools >> Extensions and listing what is there. Normally problems like these are caused by shortcut keys in extensions - e.g. the FoxyTunes extension uses CTRL+Left and CTRL+Right for default actions. I often use these shortcut keys when typing something (CTRL+Left/Right skips a word at a time) so it oftens caused problems (till I changed the keys).