oh, sorry to put you through any inconveniences
Kyatric , but it turned out to be that I had put "11q, 13" in my size property for my marble sprite instead of "11, 13"! That just goes to show that even the smallest mistake can screw up your entire project!
I just tried setting a Sprite's size to "100q, 100" in a new project and it ran just fine, no errors at all. So I assume you're mistaken and that is not the cause of the problem. Could you check for browser errors like Kyatric suggested so we can find the real cause of the problem?