<0W#25> .PST Fodler Appeared in Outlook 2003 Account Profile

Hello,

one of the users in our company network got a strange .pst folder in their mailbox. We use Microsoft 2003 Exchange Server with SP2. The folder that appeared her Outlook is named <0w#25> and it cannot be opened, or deleted either. Any time I try to proceed any activity I get a message that this folder conatins Calendar and Inbox items, but doesn’t allow me to do anything, not even a right click is active.
It can’t be found on the desktop either as an existing folder.

Does anybody know more about this or can help me to get rid of this folder.

Thanks