Cisco 7971G-GE Pass Thru Port - NOT!

I can’t get the PC pass thru port to work on my 7971G-GE. Can anybody else? I’ve tried the config files found here and 1/2 dozen other places on the 'net and it’s just impossible. Same with enabling the web access. It is possible to enable the port on the phone itself, but a reboot with subsequent config file load disables the port all over again. Advise appreciated.