How does OE set Passthrough Output device?

[fooit]

I have OE 6.0.3 running in my HTPC. It has a Xonar audiocard that I use for SPDIF signal to my receiver.
In Settings-System-Audio I set Passthrough Output device as Xonar SPDIF 5.1 but every once in a while (and very not WAF) OE looses this setting and we have no audio, so we have to set it again.
Is there any way to fix this?

In settings.xml I see the comment that the passthrough device will be properly setup on startup:

Code:

<setting id="audiooutput.passthroughdevice" type="string" label="546" help="36372">
<level>2</level>
<default>Default</default><!-- will be properly set on startup -->
</setting>