Delegate accepted meeting showing as Tentative.

This is regarding a delegate to the CEO. All of the CEO's meeting notices
are sent and received by the delegate only. Recently, she has notice that
when she accepts the meetings, they are showing up as Tentative in the CEO's
calendar. If she goes in and trys to accept them again, they still show as
Tentative. She does all her Outlook work from her desktop. No Iphones or
Blackberries are involved.

Any insite into this issue would be greatly appreciated.

Thanks in advance.
DSK