I'm not sure I fully understand your issue, but I will make a few general statements that might aid in your efforts.
If you are runnin the h.323 load on the ATA's, they will not show up under phones, instead, they will show up under gateways.
Some older ATA loads/IOS loads have issues with not correctly tagging the ATA's packets for the voice vlan. If you have a seperate voice VLAN and the port your ATA is plugged into on the switch is a trunk port, try setting it as an access port...I don't think this would be your issue if the ATA is hitting the TFTP server, but you never know.
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.