Outlook XPsp3:Meeting req. reply missing When: & Location: information

[insanity1]

I have a user that reported a problem with when a user responds to meeting requests, the reply (whether it be accepted/declined/tentative) is missing the When: and Location: information that was contained in the original meeting request sent out. The information was not deleted by the user, we have been able to recreate the problem with another set of users who are using PCs with Windows XPsp2 and Office XPsp3 (and Exchange 5.5). One person sent a meeting request to 3 others...all 3 accepted the meeting, but only one of which was returned with the information in the When & Location: fields.

Any ideas on why this may be occurring? So far, I have been unable to find any solutions.