[DiapDealer]

Ah, I see. I don't really use word-processors much myself. Definitely sounds like a bug to me, in that case. I have no idea what algorithm Word would use.

After some quick looking, it appears that Word's auto-format feature does not recognize en or em dashes as end-of-word characters. It appears to be designed (if flawed) behavior--for whatever reason. I'd suggest getting used to using one of the several shortcuts to insert open/close quotes characters directly rather than relying on auto-format to get it right. Another option is to add the closing quote before backing up to insert the en|em dash.