DCOM 10016 errors on SharePoint 2010 Servers

We used to get DCOM error 10016 on all SharePoint 2010 servers:
Log Name:      System
Source:        Microsoft-Windows-DistributedCOM
Date:          4/2/2011 12:51:29 AM
Event ID:      10016
Task Category: None
Level:         Error
Keywords:      Classic
User:          MyDomain\sp_farm_svc
Computer:      spapp.MyDomain.org
Description:
The application-specific permission settings do not grant Local Activation permission for the COM Server application with CLSID
{61738644-F196-11D0-9953-00C04FD919C1}
to the user MyDomain\sp_farm_svc SID (S-1-5-21-1055929112-3131468103-4168165710-1893) from address LocalHost (Using LRPC). This security permission can be modified using the Component Services administrative tool.
After searching for a solution, I found this Blog and we did implement the suggested method instead of using the account that shows in the error message (in my case sp_farm_svc ) we have added WSS_WPG and WSS_ADMIN_WPG as shown below:

Our issued was resolved, but we still get DCOM error 10016 for a different class:
Log Name:      System
Source:        Microsoft-Windows-DistributedCOM
Date:          4/6/2011 12:51:31 AM
Event ID:      10016
Task Category: None
Level:         Error
Keywords:      Classic
User:          MyDomain\SP_Farm_svc
Computer:      spapp.MyDomain.org
Description:
The machine-default permission settings do not grant Local Activation permission for the COM Server application with CLSID
{000C101C-0000-0000-C000-000000000046}
to the user MyDomain\SP_Farm_svc SID (S-1-5-21-1055929112-3131468103-4168165710-1893) from address LocalHost (Using LRPC). This security permission can be modified using the Component Services administrative tool.
At this point we are still working on the issue, and will post an update once we resolve it.