I'm running WinXP and Firefox 3.6.3. When I do a search, the Google results page removes all the phone numbers from the results. I can see it in source page view. Is there a conflict say from Skype or soem other add on?
I was going to suggest the Skype add-on, which I know reformats telephone numbers into links to Skype. You can try disabling it, from Tools/Add-ons: find Skype in the list, click the Disable button, and restart Firefox.