Placing a space between the @ and the reply causes the reply to NOT be directed to the person you are replying to. Which means, if they click their @Me link on their twitter homepage, they WILL NOT see your reply.
There's a GetSatisfaction thread here: #FIXREPLIES
Please post to that.
Also, to spread the word, two clicks here: http:/10ls.com/fixreplies will tweet the following to your followers:
Add your voice in favor of returning the CHOICE for all @replies http://gsfn.us/t/6g7y #fixreplies - rt plsOne click on the link, then one click on update...