OK, thanks, I understand that the methodA accessor call was dying, I was only wondering whether I could somehow easily intercept ALL method calls of an attribute in the calling class. In your example (which is helpful, thanks for that), it's not the calling class, but the called class which intercepts the methods.
I'll have to think about if I want to use it this way, it's effectively a new derived class just for this. Maybe just handling it manually in the calling class (by putting an eval around each method call) is the better way to go. Thanks for your input again!