Kmixer cannot be found - FIXED

Running Kubuntu Gutsy 7.10, kernel 2.6.22-14-generic #1 SMP

The following packages were identified by Adept Notifier for upgrade last night (2008-02-04):
linux-headers-2.6.22-14
linux-headers-2.6.22-14-generic
linux-image-2.6.22-14-generic
linux-libc-dev

After these packages were downloaded and installed, Kmix was still working (working sound, system tray icon was normal). Performed a normal shutdown of the system. After restarting my PC, sound is no longer working. The KMix icon shows in the system tray with a red X. Placing the mouse cursor on the icon shows "KMixer cannot be found". sudo find -name kmix* (from the root directory) shows that all the kmix* files are present. Adept Manager reports that kmix is installed. From a console however, echo $PATH shows: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
According to a fellow Kubuntu Forums member, who also upgraded these files but has not restarted his system, his echo $PATH shows: /home/rog/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games (note that his user home directory is included at the beginning of the path).