A question on enabling sound...

[Huub]

foo_load="YES" should go to /boot/loader.conf not to rc.conf. A good
advice would be to try to load the kld with kldload by hand and see
if it gets detected, but before loading the module please stop moused.
You can start it after loading the module and see if it's detected.
I have several loader files in /boot, but no loader.conf. There's a 
/boot/defaults/loader.conf. I suppose then that I should create a 
/boot/loader.conf with e.g. snd_pcm_load="YES" in it?