Don't know if this will do the trick but I'd try to use the syntax as Cisco defined:
Have you run the XML through the XML validator? I tried a quick push test, and all my phones return an error6 when I try that XML, so someting must be seriously wrong (Cisco claims error 6 should never happen anymore).
In my experience, host not found usually means the phone can't locate a resource (happens when you try to play a non existing file for instance, or of you're trying to play a raw file on the phone when only connected to a simulator).
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.