It seems ok on my desktop computer but not on netbook

Make sure that you do not run Firefox in permanent Private Browsing mode.

• https://support.mozilla.org/kb/Private+Browsing

You can use an extension to set a default font size and page zoom on web pages.

• Default FullZoom Level: https://addons.mozilla.org/firefox/addon/default-fullzoom-level/
• NoSquint: https://addons.mozilla.org/firefox/addon/nosquint/

You can rename the file content-prefs.sqlite to content-prefs.sqlite.old (or delete the file) in the Profile Folder to reset the page zoom on all sites.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder

Thanks - will try. The problem is only on Google home page - once I select any other page (Wikipedia, Amazon etc etc) the size of text is the same as it always has been. Maybe it is to be able to see more on a netbook screen!