Hi,
Unfortunately, Word and other word processing editors produce markup language code that's not 100% compatible with standard HTML and will corrupt the page. Auctiva's editor is spotting the corruption and trying to correct the code, resulting in those loses you noted. I've seen the problem reported many times by other Community members. It's why I asked.
Your best bet is to use a standard text editor like Notepad, and copy the text to the Auctiva HTML editor. Then add the formatting. You could use a real HTML editor and copy - paste the code. You code also try saving the Word processing document as an HTML document (might work OK).
Danno