I have one of these, and have tried lighting it from a Hot spark and gotten nowhere. I usually need to get some tinder going 1st and then light the fuel for the stove. I read some where that if you reduce part of the cube to powder you can light that to get the cube going, but I have not tried it yet.
Let me know how it works, I love this thing and keep one with my kit in the car. It may be replaced/supplimented by a home-made Hobo stove soon though. The hobo stoves I have made have worked great, and are very usefull, depending on fuel availablilty.
Mike