How can I get Firefox 3 to stop logging me out everytime I close the browser?

I close my browser often for various reasons, and having to repeatedly log into my accounts like Facebook, Yahoo, Gmail, and etc, is very inconvenient and getting gold. Firefox 2 never did this, just my current Firefox 3. Suggested Reading: Search Engine Optimization (SEO) SecretsTips, tricks, and little-known methods used by professional SEO consultants to [...]