Version information might help and also what kind of device (I assume server and OS) are you polling? I think I have seen this kind of thing with some Linux boxes... being polled through specific snmp agents.
Windows Server 2008 R2 Enterprise SP1 running on a Dell r710.
We do have other servers with this OS that we are successfully monitoring, however, this one is being problematic.
I emailed support and this was the resolution:
1. Please Stop all SolarWinds Services by going to: Program > SolarWinds Orion > Advanced Feature > Orion Services > Stop all services. (Please ensure all services are on Stopped and not Stopping).
2. Backup your SQL DataBase
3. Please run the configuration wizard: Start > Programs > SolarWinds Orion
4. Configuration and Auto –Discovery > Configuration Wizard
5. Please select all 3 options
6. Go back to the node at question.
7. With in the node details click on Poll Now.
8. Check to see if the information is been display.
I have had problems resolved in the past by even just re-running the configuration wizard... and yes it's always a good idea to backup the SQL server db before doing anything of question. Glad to hear your problem has been resolved.