Windows 7 introduces UAC and can make certain remote processes difficult if not impossible. We've always found that task in version 6 acts more in a way of the server trying initiate the job where as software delivery can be more client initiated. We have definitely had issues with 6.x task whenever there were outdated dns, vpn firewall or now UAC in place. Try remotely managing or browsing the hard drive. That will be a good start. Symantec also has an article in the knowledgebase regarding this.