When packages that are assigned to individual computers do not work, then please make sure that the computers in question are part of an AD domain.
If the computers are not and/or cannot be part of an AD domain, then you will have to manage the computers using their NetBIOS names. Otherwise, EventSentry will not correctly identify the computer names and add the local NetBIOS computer name to the first configured group.
If you cannot resolve the NetBIOS name from the computer where the management console is installed, then you can manually specify the IP address for that host.