Soundcard works but no sound... how do I troubleshoot ?

[Linuxguy123]

I am running F11 with KDE, all updates installed.

$ uname -a
Linux localhost.localdomain 2.6.29.6-213.fc11.i586 #1 SMP Tue Jul 7
20:45:17 EDT 2009 i686 i686 i386 GNU/Linux

I have sound through my headphone jack when I run system-config-sound.
It shows the PCM device to be STAC92xx Analog.

I also have sound when running Amarok.  Its not clear to me which device
it is using.

But I don't have sound with other applications (eg Youtube or mplayer or
xine) or with KDE in general.

At this point I DO have pulseaudio installed.

How do I troubleshoot or fix the sound on my laptop ?

Thanks