What version of Outlook are you using? Do you have any Rules running that
might be moving the messages? Are you using any 3rd party anti-spam filters
or perhaps you have Outlook's spam filter configured to delete messages it
flags as junk?
If you have some special setting in outlook?Check it and reset, or you can try to fix your pst file.A third part repair tool called Advanced Outlook Repair may be helpful.You can download a free demo version at http://www.datanumen.com/aor/aor.exe . I think it is a useful repair tool for you. It is easy to recover your PST file by using its wizard. It is a powerful tool to recover messages, folders and other objects from corrupt or damaged Microsoft Outlook PST files.