LowNSlow,
It's not just our C150 that has the problem, it's C150s in general. I remember the first time I flew a C150. I assumed it would be like a C152, and was amazed and outraged when I got carb ice while taxiing and waiting to take-off; I'd never had that happen before. Someone showed me why, and it's to do with the difference between the engines of the two types of courwe, but not having a memory I can't remember now. But I don't think our C150 is worse than any of the others.