You are right about the other clients. The are running as programs and not as a service.
I have had time to try your suggestions earlier today and when I changed the account on the service to the same account that I use for logging into Windows I still couldn’t connect. But I then tried running FSQL as a program instead of a service (found a tip in this forum on how to enable this) I finally managed to connect to the OPC server. So it is most sertainly DCOM issues like you suspected. Do You have any suggestions on how to proceed hereafter?
/Henrik Wendt