Cisco network monitoring in SCOM2012 SP1

I've setup a new SCOM2012 SP1 gateway for monitoring specific devices at the customer location(s). Succesfully added them but after the discovery they're all greyed out and in critical state. Hereby the list of Cisco devices I've added:

Well, I think there's something wrong with the setup of this. The Run As-account has the correct community string. Disabled SNMP trap on the gateway server, the SNMP service is started (started as a Local System Account) and have these settings:

Is this correct or?

Check errors:

SNMP GETTask 
DescriptionStatus:SuccessScheduled 
Time:5/31/2013 3:34:35 
PMStart Time:5/31/2013 3:34:35 
PMSubmitted By:........
Run As:Run Location:Target:Target 
Type:Node
Category:Operations
Retrieve the value for an OID from the Network Device via SNMP GET request
Task Output:SourceDestinationVersion2ErrorCodeFailureObject IdentifierSyntaxValue

SMMP Walk 
Initialization of a module of type "SnmpWalkWA" (CLSID "{C3713D4D-B1FF-4835-A644-8EF774830FA2}") 
failed with error code The file exists. causing the rule "System.NetworkManagement.Monitoring.SnmpWalkTask" 
running for instance "10.96.6.1" with id:"{B7FE6170-3995-02AC-66F9-DAD35283E2AC}" in management group "xxxxx". 
Error Code: -2130771961 (Unknown error (0x80ff0007)).