Avid Pro Audio Community - new mbox 2 pro installing trouble, LED lights gone

I am having problems getting my Mbox 2 Pro to work on my PC laptop (Windows XP).

(Previously, I was using the Mbox 2 mini. I had no trouble with that unit)

The problem seems to be similar to the one described in this document: http://reviews.ebay.com/Mbox-2-PRO-T...00000006132298

I plugged the Mbox into my laptop using a 6-pin to 4-pin FireWire cable, and plugged it into the wall using the power adapter. The LED lights at first came on immediately. Windows automatically installed a driver labeled in my Device Manager as "Mbox 2 Pro Bootloader."

I opened Ableton Live, but I wasn't getting any audio out of the Mbox. The LED lights were still on. Next I tried ProTools 7.3.1, but it did not detect any hardware. I closed ProTools and I tried resetting the computer. Somewhere in there, I realized that the LED lights were no longer working.

I tried unplugging and plugging the FireWire cable. I tried the "Repair" setup option for ProTools. I then tried uninstalling and reinstalling ProTools and its drivers, along with the "Mbox 2 Pro Bootloader" driver. Nothing revived the LED lights.

A key obstacle is that:
I also downloaded the Firmware Updater 1.38 and tried to run that. I immediately get a long error message saying that it does not detect a valid version of ProTools on my computer. It suggests that I upgrade to version 6.8 or 7.0, or that I uninstall and reinstall the software, because it is damaged. I've repeat the steps a few times, but can't get anywhere.

Any suggestions?