Media Player sound in Senryu and Haiku

Both of these OSes are natively installed on my EeePC 901 and I'm current using Senryu 29143 and Haiku 29155.
I had a problem with media player sound in Senryu and found that I needed to make quite a few changes in Media Preferences to get any sound at all. Even then, sound only came from the computer speakers and not from the headphones. In addition, sound quality was not perfect being a little scratchy and wobbly.
Also, it didn't seem to remember the Preferences settings between boots.
Then I booted yet again and this time, very mysteriously, sound worked from the start without the changes that seemed to be required before.
Also, this time sound did come from the phones (in addition to the computer speakers). But to mute these latter, I just had to change

Intel HD Audio>>jack-int-speaker-mode from mix2 to mix3

In Haiku, however, I have no media player sound and the Intel HDA driver module just doesn't seem to be present.
I've posted to the Senryu forum about this. Maybe I'll get some help.