>Did you grant the group in question overall DCOM rights on the server?

Thanks Erik, that did it, the *overall* DCOM rights. I added the group to the Default Security settings and now any user who instantiates this COM server now uses the same instance. Data session is set to private (I am using the VFP SESSION class to achieve this) so each user has his own data session.

[I had no idea that the Default Settings had any effect when settings are explicitly set on the specific COM's properties.]