You can set the pref browser.sessionstore.privacy_level to 2 (never) or 1 (non-HTTPS, default in Firefox 3 versions) on the about:config page to disable saving cookies via session restore.

• http://kb.mozillazine.org/browser.sessionstore.privacy_level

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

• Use the Filter bar at to top of the about:config page to locate a preference more easily.
• Preferences that have been modified show as bold (user set).
• Preferences can be reset to the default via the right-click context menu if they are user set
• Preferences can be changed via the right-click context menu: Modify (String or Integer) or Toggle (Boolean)

ok thanks, this seemed to work. when i set it to 1, and i put my privacy settings in the options back out of private browsing mode, I can now save my tabs, but it deletes the cookies. This is just how I had it before the update. It seems silly that you can't just delete the cookies on closing, as it did fine before the update. Mozilla needs to sort this bug i think

Actually, this hasn't worked properly. Now google does not recognise that I can accept cookies, so I can't log in to my googlemail account. Even though It is set to accept cookies. bizarre

okay strangely it was blocked in my cookie exceptions. no idea why but i guess my fault lol