Hi, there are a few possible causes. Based on your comment about DNS, I'd refer you to this article on DNS scavenging:
www.symantec.com/docs/HOWTO100988
I've seen this a few dozen times over the years. Macs look at the dhcp/dns "cache" rather than at the live data so it's important to keep the dns cache in sync with the live data.
I'd also suggest that you run the following to ensure the name is set correctly on each mac:
scutil --get HostName
scutil --get LocalHostName
scutil --get ComputerName
If these are all correct then it's doubtful there's a problem with the local mac client (non-altiris) configuration. If any are blank, you should set them. The "--set" option with a name will set the corresponding value: "scutil --set HostName mynewmac".
Also, run 'aex-helper info' on these mac clients to identify matching/identical resource key names and values. If any resource key and its value match on two or more computers, they will be merged.
This article shows more about the 'aex-helper info resource' command plus lists a few articles to help avoid and resolve issues with matching resource keys:
http://www.symantec.com/docs/HOWTO98421
Let me know if you have further questions.
dougj
Symantec