Strange behaviour with imported Word files

I am starting a new RH project using source docs that were done in Word.

I saved them as plain text and then copied them into my RH topics, and made a lot of edits.

Then I realized that some times when I am editing a topic, a bunch of the text below just disappears. Then if I hit Enter at the end of the last visible text, the "hidden" text reappears.

I switched to HTML view to see if anything stuck out, and when I went back to Design view, the entire content was gone ! Then I hit Enter, and it all came back.

Anyone know what is causing this ?

Is the only way to cleanly get Word files into RH to Import them ? When you do that it creates a bunch of files which I don't like.

I'd rather not start over from scratch with the source files.

Thanks