I use binary compatibility. I also have some components that is cross referenced by other components.<BR><BR>It does not matter whether I break compatibility or not. In some cases, I have no choice if I change the function signature, I have to break compatibility. The OUT OF MEMORY just keeps coming up. I agree with you that the problem does not occur in Windows 2000. Unfortunately for this project, we are working in NT4.0.<BR><BR>Appreciate any more input or insights you have.<BR>