If the problem is at run-time, give a good description of the behavior and any relevant information about your system setup. Include a working e-mail address in your signature. Every data member inside your object should clean up its own mess. If a constructor throws an exception, the object's destructor is NOT run. This tells the compiler that the data member is allowed to change during a const member function.
Some people believe that the purpose of inheritance is code reuse.
In other words, inheritance is mainly a specification technique rather than an implementation technique. Smalltalk lets you make a subtype that isn't a subclass, and allows you to make a subclass that isn't a subtype. Therefore you're usually better off NOT putting the data structure in a class. I like to think of the difference between an ATV and a Maseratti. A Maseratti, on the other hand, gets you there faster, but it forces you to stay on the road.