http://www.7is7.com/software/firefox/shortcuts.html
https://support.mozilla.org/en-US/kb/keyboard-shortcuts-perform-firefox-tasks-quickly

Ctrl + E selects the search bar - all the way back to Firefox 2.0 versions (and maybe earlier - that's the oldest version I currently have installed)

Alt + Home opens the homepage in the current tab
Ctrl + Home opens the homepage in a new tab

Is it possible that you had an add-on installed which changed that action?

No, it's possible i tweaked it, but I don't remember how

The KeyConfig extension allows keyboard commands to be modified.
http://mozilla.dorando.at/readme.html

There is a KeyConfig support thread here to help with setting it up.
http://forums.mozillazine.org/viewtopic.php?t=72994

Ctrl+Home only work if you click the toolbar Home button AFAIK and not as a keyboard shortcut as Alt + Home.