I have a similar problem which is disconcerting but I'm not sure it's fatal.
Usually I type my text but often I copy and paste from other sources. PSPad changes punctuation as displayed in the HTML edit window, but when I open the file in my browser, in Notepad++ or in the browser's View Source tool, it's fine. Some of the changes I notice in the PSPad edit window: Single quotation marks: "*_Harper's apartment_*" became "_*Harper
