Waiting for a firmware upgrade for fixing anything to do with the radio portion of the Treo 750. I have had a 700 (actually on the 5th now) and all with the same problems that you describe; full signal showing and dropped calls. Treo makes a wonderful PDA, but the phone part of the equation is as bad as the PDA is good. In Florida, where the land is flat and towers plentiful, the phone works fairly well' but back home in Illinois, where the towers are farther apart, using the phone initializes one footitus. Move your head either one foot to the left or right and the signal is right there. Otherwise, you get dropped calls, no calls, or no service. This is true whether it be Cingular or Verizon. When calling either of those carriers, they both say the majority of repairs are Treo's. I finally gave up on the phone, Palm is resting on its laurels!