Messed Up The Sent Items Folder

I got my Vista computer 12 days ago and am trying to transfer stuff from my old XP. I created several "users" for different purposes and imported all my old messages from OE6 with no trouble. After a week I decided I didn't need all those users and now want to consolidate and move the old as well as the newest messages from to one users account to another.

I was doing fine as long as I drug the .eml files into an open Mail folder. But since the old Sent Items folder was very large I tried dragging it (after copying it to the Public area and changing the ownership) directly into the Windows Mail Local Folders area. When I opened up Windows Mail it did in fact show all of my old messages. But it wouldn't open any of them, and worse yet, it won't let me delete the phantom messages. If I drag any the .eml versions of those messages into the folder they show up as duplicates, and those are both readable and deletable. I need to know either how to find and delete the phantom files, or else how to recreate the Sent Items folder.