An interface was polled by PM for a very long time. Recently noticed the same interface is no longer polled. It came to light because the dashboard data for the device was empty.
The device interface had an admin status down, by default these are filtered out in PM.
Release : 3.7
Component : IM Reporting / Admin / Configuration
Cleared the admin down status message from Cisco device and then rediscovered the device and now the interface is polled again.