Thanks Paul for your reply. The pasting with special-unformatted test does clear the box for the pasted destination. Now I need to know why this situation occurs in the first place.

Try this. Open a new word document and place some text in the properties-comment field. Copy and paste (just normal past not special) that text into the body of the document. Do you get these boxes? If not then have I got some kind of preference set? If you do get the boxes, you should see that these are not text boxes nor borders like you can put in tables. I could find no way to treat these boxes as borders.