To clarify...
Do you mean that person A has an appointment in her calendar and has chosen the "busy" option. You view her schedule from your meeting planner in Outlook, for example, and she appears to be free. Yet when you go to person B's computer and view person A's schedule from there, person A appears busy?
Is this what you mean, or have I misunderstood. If this is the case, I have no answer...sorry.
Cd.