Is this preventing you from doing something you're trying to do or are you just curious as to why you're seeing this? It's normal for the debugger to encounter errors when attempting to display information about properties that have not been initialized. For example, if you create a new IPoint object and look at its properties, you'll see exceptions are thrown for properties such as M, X, Y and Z. However, after you set the coordinates for the new point (i.e. call PutCoords), these properties then will display actual values. Unless you're encountering some type of problem, I wouldn't worry about it.
