The same security issues were also addressed in Thunderbird, Camino and Seamonkey (both based on Gecko 18.104.22.168).
These are serious issues that have been addressed. Stay safe, surf safe. Update now.
MFSA 2006-64 Crashes with evidence of memory corruption (rv:22.214.171.124)Firefox download page
MFSA 2006-62 Popup-blocker cross-site scripting (XSS)
MFSA 2006-61 Frame spoofing using document.open()
MFSA 2006-60 RSA Signature Forgery
MFSA 2006-59 Concurrency-related vulnerability
MFSA 2006-58 Auto-Update compromise through DNS and SSL spoofing
Camino Release Notes