WMI request (Wbemtest), access is denied to domain computer

let me explain our setup first!

We have 2 site location with Cyberoam CR50ING Firewall, IPSec between the 2 Subnet. Cyberoam firewall has an AD authentication with their software linked to the appliance, to detect live and logoff user. Site A is working #1.

Site B, was under a different domain. Live user was working. We migrate all of them to the same domain as Site A. They share the same GPO, firewall is off.

The main problem is: Since then, all WMI request to DC and domain computer are "access is denied" 0x80070005.

Fileserver is working (the only server getting WMI request).

I cannot get that live user working, since it is sending WMI request to the DC to grab the info in the event viewer (security tab, for user logged in/out).

I wentto dcomcnfg, making sure it was well setup, but it is still an issue.

Any idea is appreciated :)

Thanks

Christ!