Wile using the touch pad on my laptop, the home page display became hugely magnified and doesn't fit on the screen anymore. Re-booting doesn't help. It doesn't happen with other browsers - just the google home page on FireFox
Display looks like I zoomed in on it. Can't find a way to zoom back out. Change seems permanent. Only affects my home page - Google.com
Opaite Mbohovái (1)
Did you try Ctrl+0 (zero) to reset the zoom.
You did that with by holding the control key and scrolling on the right edit of the pad, which is equivalent to Ctrl+scrollwheel on the mouse.
Ctrl+0 to restore zoom to normal (Ctrl+- zooms out, Ctrl++ zooms in )
The problem with the Zoom toolbar buttons (+ and -) builtin to Firefox 4 is that there is no way to zoom directly to normal (100%) nor even tell what zoom level you are at.
For more control over zooming things see these zoom links
To set the zoom permanently on a per site basis, try the NoSquint extension, which optionally remembers on a per site basis.