esd does not start with ua-5 in 24bit-mode

[dm]

My USB sounddevice Edirol UA-5 works either in normal 16bit mode or in
an "advanced" mode with 24bit and 48 or 96 kHz. The normal mode is
supported by OSS and ALSA, the advanced mode works with ALSA only AFAIK.
Now in ubuntu, when the device is in advanced mode, esd refuses to
start, giving the following messages:

SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 44.1Khz, stereo, 16bit failed
Trying 44.1Khz, 8bit stereo.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 44.1Khz, stereo, 8bit failed
Trying 48Khz, 16bit stereo.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 48Khz, stereo,16bit failed
Trying 22.05Khz, 8bit stereo.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 22.05Khz, stereo, 8bit failed
Trying 44.1Khz, 16bit mono.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 44.1Khz, mono, 8bit failed
Trying 22.05Khz, 8bit mono.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 22.05Khz, mono, 8bit failed
Trying 11.025Khz, 8bit stereo.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 11.025Khz, stereo, 8bit failed
Trying 11.025Khz, 8bit mono.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 11.025Khz, mono, 8bit failed
Trying 8.192Khz, 8bit mono.
SNDCTL_DSP_SETFMT: Invalid argument
Audio device open for 8.192Khz, mono, 8bit failed
Trying 8Khz, 8bit mono.
SNDCTL_DSP_SETFMT: Invalid argument
Sound device inadequate for Esound. Fatal.

which is not really surprising - the right settings would be 48kHz,
stereo, 24bit. I wonder which driver esd uses, and how I can force it to
use alsa if necessary? I got the device working in advanced mode with
arts and jack on gentoo (using alsa).
The necessary module (snd_usb_audio) is loaded.

Together with bug 1943, this makes it difficult to start gnome.

In "normal" mode esd starts, but the sound is distorted.

David