Firstly I could not believe all of my text went into thin air without any notification! Aaah! (sigh).
Anyhow, Could you please let us know which version of Firefox was finger print logon was working? I suspect it was version 2.0.
The reason is this link : https://addons.mozilla.org/en-US/firefox/addon/4790
The above link shows that the fingerprint logon only work from version 1 to 2.0 of Firefox.
The spell checker depends on which spell checker addon were you using? English version? Tamil version etc... Also the name of the addon would help us to pin point the version compatibility.
Usually the compatibility is given if you click on the addon detail option.
This is the link of spell checker which works with Version 3.5 https://addons.mozilla.org/en-US/firefox/addon/11259
Could you please let us know the version numbers and perhaps the names of the exact addons for us to find out the solution for you?