Sometime in the last few versions (I am using 2.48 now), there was a GUI change that caused Unicode tags to not display properly in some text fields: the left hand side text panel, the popup "edit tag info" box and the properties box. Unicode text does show properly in the actual file list and in the extended tags popup window.
I have experienced the same thing. The unicode character is written correctly within the file and visible when viewed using the "Extended Tags" dialog, but not displayed properly in the main UI.
