TV Tuner not found in Device Manager in XP Embedded

Question

my first question on here, and it will probably my most important one.

I've been working for a small company for a month and a half, and have recently been tasked with doing things I've never done. Namely, and most annoyingly: configuring an XP Embedded image.
This wouldn't be such a problem if only I had been able to acquire ALL hardware devices I need for the task, before making the final image.
In general, all hardware has worked, with minimal fuss, except maybe the Sierra Wireless C889, which still shows a Found New Hardware window, complaining about an .ini. This isn't a big issue luckily.

What I really need help with is this:
The TV Tuner card is not detected by XP Embedded, whatsoever.
Not in device manager, not in Unknown Device Tool, and I'm unsure of what other software I can run to check.

Some more information:

• The TV Tuner is picked up by XP Pro, and has been previously tested working with it (I watched a World Cup match with one)

• The stable test machine doesn't pick up the TV Tuner with XP Embedded, so it's probably not some extraneous problem with one of the final, production machines.

• The chip on the TV Tuner is an ITE IT9135FN. It doesn't exist, from the looks of things, ITE has no information on it on my last check, but I have supposedly BDA-compatible drivers for it, and they were installed, with no errors given.

• The XP Embedded build had the Digital Set-top Box template applied, along with the other Set-top Box templates, just for good measure.

• The TV Tuner is not custom, but it's not widely available either. It has no model number.

The specs of the test machines are:
- Zotac IONITX-F-E - 2GB DDR2 single
- 160GB WD Scorpio Blue
- 90W Pico-PSU
- RaLink-based RT73 embedded-USB WiFi
- Sierra Wireless Compass 889

This problem is doing my head in, and have been searching endlessly, but I either haven't found the golden search phrase yet, or I just haven't looked hard enough for the answer (although I've bloody-well tried).
Before someone suggests componentizing the driver, building the target image again, and replicating all over again; that's been suggested to the boss multiple times, he says it's a no-go.

Thanks in advance guys and gals of superuser.
I may well give some form of present to anyone that can get this to work successfully.