Create a new profile as a test to check if your current profile is causing the problems. See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

Profile Backup and Restore

• http://kb.mozillazine.org/Profile_backup
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Thanks, these instructions are for Windows PC, but I'll look at the Mac pages for it. I meant to add that I am not having the problem with my Macbook Air; same add-ons.

Created a new profile, entering everything from scratch. Just now when typing this, Firefox reloaded and wiped everything out. This is now my second attempt to reply.

Hello,

Certain Firefox problems can be solved by performing a Clean reinstall. This means you remove Firefox program files and then reinstall Firefox. Please follow these steps:

Note: You might want to print these steps or view them in another browser.

1. Download the latest Desktop version of Firefox from http://www.mozilla.org and save the setup file to your computer.
2. After the download finishes, close all Firefox windows (click Exit from the Firefox or File menu).
3. Delete the Firefox installation folder, which is located in one of these locations, by default:
   • Windows:
     • C:\Program Files\Mozilla Firefox
     • C:\Program Files (x86)\Mozilla Firefox
   • Mac: Delete Firefox from the Applications folder.
   • Linux: If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it - see Install Firefox on Linux. If you downloaded and installed the binary package from the Firefox download page, simply remove the folder firefox in your home directory.
4. Now, go ahead and reinstall Firefox:
   1. Double-click the downloaded installation file and go through the steps of the installation wizard.
   2. Once the wizard is finished, choose to directly open Firefox after clicking the Finish button.

Please report back to see if this helped you!

Thank you.

WARNING: Do not run Firefox's uninstaller or use a third party remover as part of this process, because that could permanently delete your Firefox data, including but not limited to, extensions, cache, cookies, bookmarks, personal settings and saved passwords. These cannot be recovered unless they have been backed up to an external device!

Can you attach a screenshot that shows the garble issue?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

Use a compressed image type like PNG or JPG to save the screenshot.

In case you are using "Clear history when Firefox closes":

• do not clear the Site Preferences

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings
• https://support.mozilla.org/kb/Clear+Recent+History

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, and passwords in addition to site settings for page zoom among others .

You can do a check for corrupted and duplicate fonts and other font issues:

• http://www.thexlab.com/faqs/multipleappsquit.html - Font Book 2.0 Help: Checking for damaged fonts
• http://www.creativetechs.com/iq/garbled_fonts_troubleshooting_guide.html

Hi everybody, thanks for your messages. I did a reset first; now have done the clean install. Restored the add-ons and plugins; and the garble issue has disappeared, at least for now. I did a sync with my MacBook Air for bookmarks. (Garble still occurs on my old MacBook Pro; so I was able to duplicate at least one problem.) Something is still reloading, but not as often. I'll go back to the MBP and get a screen grab. I wish I could do one on this iMac for before & after zooming, but can't anticipate when it reloads and/or the zoomed-in text loses hold. Thanks again....

The zoomed text just now lost hold but didn't destroy what I'd typed....

When you refer to zooming, is that Firefox's built-in zoom feature, or a Mac feature that works on all programs?

In case it's relevant, on Mac, you have these shortcuts to change the zoom level:

• command + 0 (zero) = reset to default zoom level
• command + = larger
• command - = smaller

You also can change the zoom on the page using the mouse scroll wheel (or perhaps a particular zone on the trackpad) when the command key is held down.

Everybody cross your fingers. It's behaving right now. Thanks again for all the suggestions; and HAPPY NEW YEAR!!