What version is the LifeCycle controller and BIOS on the 11G server (iDRAC6)? What is the server model? One other thing you can try is to restart the iDRAC once.
Our installaion is an upgrade from OME 2.1 (where we also had the issue)we use WSMAN to inventory our DRACs and they are marked as unclassifiedNote: on a OME 2.0 test server, using the same configuration, all is working as expected.The troubleshooting tool is working normal, when selecting WSMAN and these options Skip CA CheckSkip CN CheckUsing winrm , there is no output and no error message?winrm e cimv2/root/dcim/DCIM_SystemView -u:root -p:****** -r:[URL] wsman:443 -auth:basic -encoding:utf-8 -SkipCACheck -SkipCNCheck -skiprevocationcheck 
OME 2.2: WSMAN inventory Unclassified