Palm Treo 755P User Manual page 309

To avoid this problem in the future, do not assign time zones to your events. Palm Desktop
software does not support time zones.
Phone
Signal Strength Is Weak
Become familiar with low coverage areas where you live, commute, work, and play. Then
you know when to expect signal strength issues.
If you're standing, move about 10 feet (3 meters) in any direction.
In a building, move near a window. Open any metal blinds.
In a building, move outdoors or to a more open area.
Outdoors, move away from large buildings, trees, or electrical wires.
In a vehicle, move your device so that it's level with a window.
My Treo Device Won't Connect to the Mobile Network
Try the suggestions in the preceding section for weak signals.
Turn off your phone and turn it on again (see "Turning Your Device's Phone On and Off"
on page 55).
Perform a soft reset (see "Soft Reset" on page 288).
If you have an active DUN session (that is, you are using your device's phone as a
modem), terminate the session (see "Using Your Device's Phone as a Modem" on
page 110 or "Using Your Device as a Wireless Modem" on page 164).
The Other Person Hears an Echo
Try decreasing the volume on your device to avoid coupling or feedback on the other
person's end. This applies to both the speakerphone and the earpiece.
Position the earpiece closer to your ear to prevent sound leaking back into the
microphone. Keep your hand away from the microphone hole, which is on the bottom
right side of the phone.
If you're using the speakerphone feature with your device lying on a flat surface, try
turning the device face down (screen facing the surface).
Section 7A: Help 301