I had the same problem.
LowLight Camera set outside to observe animal behavior at night
with a 25watt yellow bulb. I could make out the animals, but not very well.
The IR Illuminator that you are referring to will not work with the XX20A low lite camera as it is.
But I have read mods to convert webcams to work with IR, I believe the approach would be
the same, but your warranty would be voided. If your XX20A is over a year old, then it may be worth trying.
Infrared WebCam Modhttp://www.hoagieshouse.com/IR/My solution that I had posted under "Wireless Cameras & Vanguard"
is to go with the Swann Night Hawk Camera.
Reference Posthttp://www.x10community.com/forums/index.php?topic=10465.0125 people have viewed this post, no feedback yet.
Not sure if it is frowned upon to post alternative solutions that are compatible with AHP/iWitness,
but I needed a solution, and wanted to share my findings.