Firefox 3 Problem - Can't Add or Change Bookmarks

Subscriber Winona Leaman wrote to ask about a significant problem she was having with Firefox 3:

A question ... I'm using windows XP, with SP2, and Firefox 3 browser, which I prefer over Internet Explorer. Recently I have not been able to save, or delete my bookmarks. I have searched for solutions, but none successful, including reinstalling Firefox. Both saving, and deleting bookmarks worker for me before, so I do know the proceedure for both of those tasks. Thank you for any help you can give. I enjoy and look forward to your helpful weekly newsletter. Winona
I wrote back to Winona to tell her that I had experienced the same problem about 3 weeks ago and solved it. Of course, I told her how to solve it, too...

The key was that I had to do a "clean reinstall" of Firefox, not just uninstall and reinstall.

The steps were:

Export the Firefox 3 bookmarks
From the toolbar, Bookmarks > Organize Bookmarks > Import and Backup > Backup...
pick the location and file name to save your bookmarks for importing into Firefox later. Save them somewhere in My Documents or elsewhere of your choice — just not in the Application Data\Mozilla\FIrefox folder The filetype will be .json.
Just in case, make a different type of backup, also.
Bookmarks > Organize Bookmarks > Import and Backup > Export HTML..., which will create an HTML file of the Bookmarks. If I recall correctly, this is the file that worked for me. I think I had problems with the .json file
Uninstall Firefox:
Start > Add or Remove Programs > Firefox > Uninstall (or Remove, whichever it says)
Open Windows Explorer: Right-click on Start > Explore
If you have not already done this, set Windows Explorer to Show Hidden Files and Folders
Move to C:\Documents and Settings\[YourUserID]\Application Data\Mozilla\Firefox
Either (a) delete the Firefox directory or (b) rename the Firefox directory to something like Firefox-old
Reboot
Install Firefox
Now import your bookmarks that you saved: If I recall correctly, importing from the saved HTML file seemed to work, while importing from the .json file (the "backup file") didn't work right.
Winona wrote back to report success!

Hello ,

I would like to thank you very much for your helpful, and very quick reply to my bookmark problem. After following your great step by step instructions this issue has been solved.

Thanks again