Some gestures have been removed in Firefox 4.

You can restore the zoom feature by changing the values of the related prefs on the about:config page.

browser.gesture.pinch.in -> cmd_fullZoomReduce
browser.gesture.pinch.in.shift -> cmd_fullZoomReset
browser.gesture.pinch.out -> cmd_fullZoomEnlarge
browser.gesture.pinch.out.shift -> cmd_fullZoomReset
browser.gesture.pinch.latched -> false

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

Thank you for your response. I accessed that page and it seems a bit complicated for those of us not accustomed to making such changes in our software. Any explanation as to why this happened? Will there be any upgrades soon that will correct this problem?

I followed the instructions give and it works fine now. I was not as difficult as I had anticipated.

THNX....I have Firefox 6.0....and I applied your suggestions...and IT WORKED! thanks again!