Your are right. Checking the logs I found that I installed "firefox-3.0 3.0.5+nobinonly-0ubuntu0.8.04.1" in December. Today I ran "apt-get upgrade" and got "xulrunner-1.9 1.9.0.1+build1+nobinonly-0ubuntu0.8.04.2" installed.
Now I am also running
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.5) Gecko/2008121621 Ubuntu/8.04 (hardy) Firefox/3.0.5
Your are right. Checking the logs I found that I installed "firefox-3.0 3.0.5+nobinonly -0ubuntu0. 8.04.1" in December. Today I ran "apt-get upgrade" and got "xulrunner-1.9 1.9.0.1+ build1+ nobinonly- 0ubuntu0. 8.04.2" installed.
Now I am also running
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.5) Gecko/2008121621
Ubuntu/8.04 (hardy) Firefox/3.0.5