As far as the code is concerned, there appear to have been several passes through it. The later passes introduced several bugs. The person or people involved do not appear to understand the Visual Basic event model.
Code review
Tools and methods are only as good as the people who use them. They are no substitute for training. Staff must know why as well as how. The why comes first.
The basics of computing—how chips work, how memory is used, what operating systems and algorithms do—are all essentials for IT professionals. The lack of this fundamental knowledge means that developers cannot use powerful tools such as Visual Basic 5 effectively. They need to understand exactly what the tool is doing and how it works. This knowledge is even more important as the tools become more powerful because they hide so much. To use distributed objects effectively, for example, one has to understand how the technical mechanisms that create the objects work, not just how to make them work. How is a local call turned into a remote call? What is the effect on the network? How does it perform with high transaction rates? What is the impact of other network traffic?
The fundamentals of software engineering must be taught to staff. The principles of data management, security, configuration management, project control, and so on apply to all development approaches. The divisions and disciplines of separate development, test, and production environments are critical to successful implementation. The ability to produce code quickly in Visual Basic 5 doesn’t relieve developers and managers of the duty to produce the right code and to use the technical infrastructure correctly and efficiently.