I know that some folks continue to have trouble getting the integration between VMM and OpsMgr to work. If you are getting this error, this post is for you.
"VMM service does not have the necessary privileges to access the Operations Manager SDK service on <servername>............ID: 11804"
First, i would ask that you follow the troubleshooting steps outlined in my post named "How to configure the integration between VMM and OpsMgr Part". If those don't work, follow these steps below.
If you restarted the OpsMgr SDK service (i.e. Net stop omsdk && net start omsdk) and you are still getting the error, you might want to reboot your OpsMgr Root Management Server and the VMM server. That has been known to fix any lingering permissions issues that were not propagated properly.
If your problem is not fixed, it might be a permissions issue with OpsMgr. What you need to do is to launch the OpsMgr console using the same account that the VMM service uses. In VMM 2008 beta, our service runs as local system. So launch the OpsMgr console as system on the vmm server computer using the command below. If this does not work, you need to ensure that the VMM service account (represented as <domain name>\<vmm server name>$ has the appropriate permissions in OpsMgr for this to work)
psexec.exe -e -i -s -x "C:\Program Files\System Center Operations Manager 2007\Microsoft.MOM.UI.Console.exe"
You can get psexec from this link: http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx
I hope this helps.
<update> It seems that only PsExec.exe version 1.91 works for providing a console session as System.