After upgrading to Carbon Copy Solution 6.2.1144, connections are no longer possible using native NT security.
In the 6.1 release of the Carbon Copy Solution, Native NT authentication was the default authentication type. The local Administrators group rolled out to each Carbon Copy Agent by default. This was done in order to allow customers to access their Carbon Copy Agents prior to the initial Carbon Copy Agent configuration rollout.
In many cases, customers would simply roll out the Carbon Copy Agent and attempt a connection. Once presented with the authentication dialogue, the user would enter his or her network credentials. If this particular account was a member of the local administrators group on the Carbon Copy Agent system, the connection would be successful.
Because of security reasons, many customers requested that the Administrators Group be removed from the Carbon Copy Agent profile definition. This was done with the release of 6.2. This is why customers can no longer connect after upgrading to the 6.2 version and with Natvie NT Secuirty enabled.
A solution to this would be to simply reapply the Local Administrators group to each Carbon Copy Agent. This can be done by accessing the Altiris console and then accessing Carbon Copy Agent configuration page. Click on the Authentication tab and enter Administrators into the Add Local Group field. Once this is done, the Carbon Copy Agents will have the Local Administrator group applied and active. Here is an example: