For all who have had this problem. I used the "speed key" k and accidently sent all May 2011 emails to this folder. I was able to retrieve them by searching for "2011" and refining my search to the @C@Chats folder (which was displayed), select those files and move them to my inbox. I retrieved them all. If you can figure out a similar search that encompasses your lost emails you can probably get yours back too.