When Outlook is adding or subtracting 2 - 8 minutes to new appointments, its not a bug in Outlook, ghosts, or gremlins.
Its caused by the anti-spam module from CA Security Suite 2008. Disabling or uninstalling the anti-spam module will fix it.
For example, if an appointment is created
for 10:00 to 11:00 AM, it's changed to 10:02 to 11:02 AM. Users may also
receive an error message that the message is not recurring and they need
to close all open items.
Appointment times randomly move by 2 - 8 minutes first published in EMO, Jan 2009