Okay, so it was raised today. Someone said you can, i said you can't. We went to visit the physics teachers chilling in their little prep room, and asked them.
It turns out that in order to run on custard, you need to get custard powder, but instead of adding the right ammount of water, add only a tiny bit. Then you can run along it (but not stand still on it) as it's essentially the consistancy of slightly melted cheese.
Now here's the debate: Does this really constitute custard? I don't think it does. See, i think that custard is this desert (topping) that i eat - not a bunch of powder that gets mixed with water. That isn't custard, in the same way that bread with only a few grains of flour isn't bread. Water is a key ingredient, and if you have to severely curtail that in order to be able to run on it, i don't think it's really custard, not to mention the fact it hasn't been 'cooked'.
So.... We know that you can run on this mystery, custard-LIKE substance, but not real custard itself, i put the question to you:
Can you run on custard?
I believe not. That substance is not custard.