It might be because it simply didn't send from there computer, so they could try PMing the message again. Also, the forum dislikes when people have the same forum names, so if there's someone with the same forum name as you, it could've been sent to them accidently. Ask them you PM it to your username, or you can change your forum nickname. (I do not know if any one has the same nickname as you, but you can check in "members.") I checked, and people have the same forum nickname as you- you'll have to tell them to PM it to your username instead, or change your forum nickname.