TonePort UX2 recognized but won't play audio

I see the card in the audio settings manager, but this message is repeated in the syslog:

kernel: [ 86.246910] line6usb 6-1:1.1: URB out #0 submission failed
kernel: [ 86.246908] line6usb 6-1:1.1: URB out #0 submission failed
kernel: [ 86.246908] line6usb 6-1:1.1: URB out #0 submission failed

Nothing I do seems to fix it! Help!

ProblemType: Bug
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: don 1842 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Line6USB'/'Line6 TonePort UX2 at USB 6-1:1.0'
   Mixer name : ''
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card1.Amixer.info:
 Card hw:1 'Line6USB_1'/'Line6 TonePort UX2 at USB 6-1:1.1'
   Mixer name : ''
   Components : ''
   Controls : 1
   Simple ctrls : 1
Date: Sun Dec 20 16:21:49 2009
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=9ebb45ad-4de0-46ab-9884-d029d28db3db
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
MachineType: System manufacturer P5K-E
NonfreeKernelModules: nvidia
Package: linux-image-2.6.31-16-generic-pae 2.6.31-16.53
PciMultimedia:

ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-16-generic-pae root=UUID=6a602b3e-722b-49ed-ba47-37fea1d0c83d ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-16.53-generic-pae
RelatedPackageVersions:
 linux-backports-modules-2.6.31-16-generic-pae N/A
 linux-firmware 1.24
RfKill:

SourcePackage: linux
Uname: Linux 2.6.31-16-generic-pae i686
XsessionErrors:
 (gnome-settings-daemon:1856): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1856): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (polkit-gnome-authentication-agent-1:2004): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
 (nautilus:1985): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
dmi.bios.date: 06/26/2007
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0503
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P5K-E
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0503:bd06/26/2007:svnSystemmanufacturer:pnP5K-E:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP5K-E:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: P5K-E
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer