IPS exclusion not working

Hello,

one of our customers reported the following issue:

An IPS exclusion for a Win 7 Prof. client with SEP 12.1.6 MP1 has been created. The client updated the policy correctly after the changes have been made to the policy but the administrators still receive NTP and compliance event notifications (MAC-spoofing) for this specific host.

Any idea what this could be?

Thanks in advance!