Outlook 2007 emails received but not displayed

I have an admin user with Win XP2 Office 2007 Pro on a laptop and lately whenever they click on send and receive you can see the progress bar of emails being received with no errors, but the number of email received in this progress bar does not appear in their inbox, junk mail anywhere.

They could have 5 unread emails before clicking on send and receive, they click and the progress bar says “receiving 1 message of of 50, and it shows that it is downloading 50 emails but no where can 50 new unread emails be found.

There are no rules/actions set on this .pst file, evrything goes into the inbox. Where are these emails supposedly and how can I fix this problem?

Any ideas appreciated.