Trouble routing aux to MOTU 828 mkII Analog 7-8

Friends,

Help! I’m trying to route the #1 aux buss to Analog 7-8 on my MOTU 828mkII for use as a headphone mix, but I’m having trouble. Here’s what I’m doing:
Using ASIO drivers.
Hit ‘the hammer’ on Playback VU-Meter, then ‘Select I/O channels’ button, checked MOTU Firewire Audio and MOTU Firewire Audio-8 checkboxes, then OK. Playback VU-Meter adjusts to show 2 more meters.
Choose Folder icon, then double-click a WAV file. Track shows fine.
In Mixer window:
* Bring up Aux1 fader on Track#1 to about +5.4dB.
* Across the top, bring up Master Channel #1 and #8 return from aux channel #1 volume to +0.8 dB
* Both #1 and #8 are set for Pre-master effects and Pre-master volume.
Hit Play.
Lotsa clipping, so back off ‘knobs’ at top of Mixer window a bit to lower volume somewhat.
Here’s the problem: I’m getting great signal on all meters in N-track, but the MOTU isn’t lighting up the output LEDs, and I get no signal from Analog 8. Nada, zip.

OK, so let’s try another test:
In Mixer window, bring Aux1 fader to -Inf., and bring return faders to -Inf.
In Main window, double-click track name to show Track properties dialog.
In ‘Output to:’ field, drop down selection list and choose ‘3 - MOTU FireWire Audio - 8’, then click ‘OK’.
The track output identifier shows ‘Error’. but the Playback VU-Meter shows activity when I hit play - and there is still NO SOUND.

Help! What am I doing wrong, and/or what is wrong?

The interface appears to be working properly in Acid Pro 5.0 - I was able to assign Analog #7-8 as the stereo output and did hear sound.

I think N-track can do this: in the FAQ (yes, I RTFM), question 5.b gives directions. Am I missing something?

Please help!!!

DScott