I have never had a soup made with cream curdle, even upon boiling. What exactly do you mean by curdled? Did you see lumps almost like cottage cheese (curds) or did you see an oil slick on the surface (broken)?
If the latter, then you probably used too much fat to saute your veg and pancetta, especially since pancetta will render fat of it's own thereby increasing the fat content and the possibility of breaking the soup. Roux or another thickener will take care of that issue.
If the problem was that it truly curdled, what was the date of the cream? Also did you use cream, or half & half, or milk? Cream can take the high heat, half & half to a degree, milk not so much without a thickener.