Thank you for opening this bug and helping make Ubuntu better.
Have you run, from a terminal, "sudo dpkg --configure -a" (without the
quotes) as suggested by the error message?
** Package changed: firefox-3.0 (Ubuntu) => dpkg (Ubuntu)
** Changed in: dpkg (Ubuntu)
Status: New => Incomplete
** Attachment added: "Dependencies.txt"
http://launchpadlibrarian.net/21242783/Dependencies.txt
** Attachment added: "ExtensionSummary.txt"
http://launchpadlibrarian.net/21242784/ExtensionSummary.txt
** Attachment added: "pluginreg.dat.txt"
http://launchpadlibrarian.net/21242785/pluginr
