That’s ok and normal. If sound problems occur, keep a note of what you were doing just before/when it drops.
With PulseAudio, KMix and alsamixer (same on KDE’s Settings > Multimedia > Phonon) will only show one channel per device (sound chip/card). KMix > Settings > Audio Setup, will take you to the Phonon settings where you can make adjustments on the Speaker Setup tab and test speakers. The KMix tab “Playback Streams” will show a volume adjustment channel/scale for each separate application stream playing at the same time.
With sound problems on 11.3/KDE/ALSA, I can understand why you installed 11.4 in the hope it would provide more stable audio. However, if the sound problems continued on 11.4, in my opinion upgrading KDE 4.6.0 to 4.6.3 introduced an unnecessary complication, and possibly extra problems. For example, the procedure used by YaST for disabling/enabling PulseAudio was tested and released with KDE 4.6.0, but might not work properly with the 4.6.3 version.
If there are problems, you are likely to be more successful with “problem determination” and support here in the forum, when you remain with standard releases of system components (plus official patches/updates from Update repo), including the DE. 