SNMP Service can't connect with Caché SNMP agent

Whenever the Windows SNMP Service restarts, the snmpdbg log says the following. 

13:08:59 :Attempting initial TCP connection(s) with 1 Cache instances ...
13:08:59 :Get connection with ENSEMBLE on port 1972
13:08:59 :Connection refused on port 1972, check if Cache instance ENSEMBLE is started.
13:08:59 :Cache iscsnmp.dll initialized for 1 configs

Ensemble and all productions are running. I've set up Caché SNMP agent on many other servers in our company and those are working fine. However this one server won't budge. 

Does anyone have any idea what the problem may be here? 

Regards,

Glenn