We did a 3.3 upgrade last spring just so we could start using 7941G and 7961G IP Phones. The support for these phones was added in CCM 3.3.5 SR1. We actually went to 3.3.5 SR2 due to the amount of bug fixes and the 7961G phones worked perfectly. Have a look;
Supported CallManager Versions
The Cisco IP Phone 7961G and 7941G firmware release 7.0(2) is supported on these Cisco CallManager versions:
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.