Several times a minute? There are a few things Firefox does on a very regular schedule. One of them is update its snapshot of your open windows and tabs for crash recovery purposes -- every 15 seconds. You could try extending that to 60 seconds to see whether that helps. Here's how:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box that appears above the list, type or paste session and pause while the list is filtered

(3) Double-click browser.sessionstore.interval and change the value from 15000 to 60000 (this value is in milliseconds: 15000/1000 = 15 seconds, 60000/1000 = 60 seconds). I don't know whether this takes effect immediately or the next time you start Firefox.

Does that help?

If that doesn't make much/any difference, have you set up Firefox Sync?

You can check for problems with the sessionstore.js and sessionstore.bak files in the Firefox profile folder that store session data.

Delete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox profile folder.

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Multiple_profile_files_created

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).