COM+ Permission Denied

I have a public not creatable class in one of my ActiveX Control.
This public createable class is stored in dictionary object as items.
The dictionary object is passed to a DLL which is loaded under COM+.
Now when i m accessing the public not creatable class using Server MSI in server machine,it works fine, but when i m accessing the public not creatable class using client MST in client machine i get an error "Permission Denied-Error 70".
I have unchecked the authorization checks and enforce component level access check but the permission denied problem still exist.