Hi,
Really thank you for your concerns. But I failed to reproduce the problem with small files. The .pas unit that caused the problem was originally Delphi unit. When I make new unit in Lazarus, there are no problems. I could not change the encoding type of the problematic file from ASCII to UTF8(w/o BOM), by any text-editors, like MS NotePad. So I think it's not Lazarus problem --- rather, something inherent in the file itself. I just gave up, created new unit, and copied each function / procedures. If I see any similar problem again, I'll come back.
Regards,