I have a task to update some MFC COM-components to support Unicode characters (Chinese text). So far I have successfully fixed two components, so I kind of know what I'm doing. With the third component, I faced a problem where Chinese text displayd correctly on the component when it was written, but as soon as the user pressed enter or the text field otherwise lost focus, the characters changed to something completely wrong. This happened because I had both _MBCS and _UNICODE defined in the project and got fixed when I removed _MBCS. Now, with the fourth component I have the same problem but this time only _UNICODE is defined and I have no clue what causes this. In addition, the Chinese text displays correctly when it's first written to wordpad for example and then copy/pasted to component. Although this doesn't help since I have to use the component to send the Unicode text to another device and when we tested, the text is not sent correctly.