My XBEE worked fine and has been in the field for two years, but now the communication is intermittent at best. For simple operations like reading the serial number through ATSH and ATSL, they sometimes work, but there are often errors like a '"' instead of a '3' (they are one bit off in ASCII code) or sometime it is complete garbage (Z<ÇRLM n !). Trying enough times will eventually cause the command to go through, but it is extremely flaky. Sometimes the XBEE doesn't respond at all when testing the "+++" command. Monitoring the RX/TX pins on the oscilloscope showed that the '+' made it to the XBEE, but there was no respond back to the microcontroller. Replacing the XBEE restored all communications. Did I just get a bad XBEE? Is this common? Is there a work around?