Hello erdzzy,
What products do you currently have installed? The trap service behaviour may be normal.
Availability i.e up/down is calculated from the ICMP ping response from the node. If you are missing availability from "some" nodes they should be showing as down. If you are missing other stats such as CPU/MEM you should verify the nodes are responding to SNMP/WMI
1. Are the nodes that are missing stats showing as up/down/warning/other?
2. If you try to "List resources" on one of the nodes in question - do you see a list of objects such as CPU/Interfaces etc or a message saying "the node is no longer responding and maybe down
If you see the error message and the node is up, it indicates that either the node is no longer responding to SNMP, in which case you should check the string is correct / firewall rules and ACL etc on the device.
Tony.