Application problem and questions

I'm evaluating the product. I write from Italy.

I have the problem "DCOM" to scan server and client.
I have done the suggested steps but nothing.
My test are based on a domain Ms W2k3 Sp1 native mode whit client Ms XpPro Sp2.
With which customer the application carries out the scan?
admin/admin or the logged user?
Can be changed that user?
Can be changed or modificated the user /technician admin/admin whit a domain user?

Other problem is with AD user import.
The requesters import from AD duplicates users and it not overwriters or, it would be better, adds the users.
However it isn't possibile to maintain the AD password?

Tanks in advanced.