Does anyone have an answer to this? Seems like a bad bug in Altiris. I have this problem in 6.9sp4 and nothing will work around it.
I have this working for me now, but I am not sure what the exact fix was. I was seeing a bad OU name and invalid static route being applied in the modify config task.
In my opinion, this is related to bugs with Windows 7/2008/Vista when Altiris is doing commands to backup/restore IP configuration settings. (By the way, I wish there was more visibility on the commands being run by Altiris).
To fix this you should...
1. Make sure all of the IP and DNS settings are good on the target machine before you do anything else!
2. If you have an Altiris job that does the modify configuration, clear all the job history by deleting the failed operations from the Altiris console. Then ensure your jobs only apply good settings. I have made sure we specify only domain-specific settings in the modify config job, and made sure we DON'T specify anything that is 'generic' to the environment, such as default gateway. This seems to work.