so if your radio goes brain dead (no mr flip when looking for a network) try draining your batteries completely. the quickest way of doing that is to hold the jog wheel in and do a soft reset. keep holding the jog wheel until you see a red and green light sequence at the power button. this will turn on the screen with all pixels on and it will stay on until the batteries are totally flat.

when you apply power to the treo it should have lost all settings and data. then charge and do a backup restore and you should be back in business.