Have older eMac with OX10.4, previously using external modem with dial-up. Just got Verizon UM175 USB modem and data plan. Mac wouldn't recognize modem. Installed Verizon VZNavigator software, setup, and launched. It recognizes modem, shows 3 out of 4 bars signal, and did 'successful initialization' of modem. BUT when telling it to connect to web, get error message saying "backchannel port failed to initialize." Anyone have a clue what to start checking? Verizon Mac rep doesn't. BTW, modem does work with PC laptop. thanks.