old email in outlook 2003 become unread

[john1044]

Hello,

we're are running exchange 2007 sp1 & outlook 2003 sp3.
a user said some of his old emails become unread.
any suggestions on how to troubleshoot this?

 

[Bob I]

Clicking the "Mark as Unread" button does that. (as does the
Alt+keystroke shortcut)