[PD] pd, alsa, and the emi 2|6

[np]

hello list, 

just wondering if anyone out there has had any luck getting pd to work using 
alsa with the emagic emi 2|6 usb interface? i have everything correctly 
installed as far as i can tell, and alsa works fine using my internal 
soundcard, but when i attempt to run pd using the emi output (with 'pd 
 -alsadev 2') i get a bunch of error messages: 

snd_pcm_hw_params_set_format (input): Invalid argument
snd_pcm_hw_params_set_format (input): Invalid argument
ALSA lib pcm_hw.c:466:(snd_pcm_hw_prepare) SNDRV_PCM_IOCTL_PREPARE
failed: Invalid argument
snd_pcm_hw_params (input): Invalid argument
ALSA lib pcm_hw.c:466:(snd_pcm_hw_prepare) SNDRV_PCM_IOCTL_PREPARE
failed: Invalid argument
ALSA lib pcm.c:1146:(snd_pcm_link) SNDRV_PCM_IOCTL_LINK failed: File
descriptor in bad state
ALSA lib pcm_hw.c:494:(snd_pcm_hw_start) SNDRV_PCM_IOCTL_START
failed: File descriptor in bad state
snd_pcm_start: File descriptor in bad state
Using ALSA interface
audio I/O stuck... closing audio 

any help would be much appreciated! 

best,
nick