Problem Monitoring Active Directory

hello, this is my first time using Opmanager, i find this software very helpful, thanks for making this software, making my job way much easier and saving much time..., i have a slight problem.., i already instal the software and assigning it to monitor some of our infrastructure device.., all device were detected and giving us allot of information.., but it cant monitor the Domain controller, i've followed the help file related to this problem.. but i still cant fixed it.. it says that the software didn't collect the data due to the WMI problem.. i've checked on the DC, the WMI was running properly.. please some one kindly help me how to fix this,did i miss configure it or it just my short knowledge.. since i was new as a system administrator.. any reply are welcome, thanks before

Regards

Coblain
email : coblain@yahoo.com