I'm trying to get audio input and ouput working on the GPStix. I did modprobe on snd-pxa2xx-ac97, snd-pcm-oss, and snd-mixer-oss as instructed in the wiki. I'v also done a modprobe on a few other modules found in /lib/modules/2.6.18gum/kernel/sound/

When attempting to record or play back audio I get this:
# brec > foo                                                                   
brec: /dev/dsp: Invalid argument                                               
# bplay foo                                                                    
bplay: /dev/dsp: Invalid argument

/dev/dsp was automatically created when I did the modprobe.

What am I doing wrong?