There is a known bug with application 8.350 through 8.371 where the Bluetooth handsfree functionality crashes after 2-3 days. Symptoms include: - Tomtom will say "phone not connected" upon power-on - Tomtom will spontaneously reboot, upon making a call or mid-call - Bluetooth calls work, but the FM transmitter stops playing after a few seconds. - Bluetooth calls get garbled on one of the two ends. If you have a GO 540/740/940, the bug is fixed in app 9.058. But due to numerous other bugs with app 9.058, you may still choose to downgrade software instead. Workarounds include: - Do a pin reset whenever this happens. This isn't a permanent fix, and the problem will happen again in 2-3 days - or Downgrade to an earlier application. First backup per this link. Then to downgrade, use winrar to extract the file below that matches your device, and copy it to your Tomtom, overwriting files when prompted. If you downgrade, you will lose the ability to broadcast directions over the FM transmitter (for models that have an FM transmitter). GO 520 / GO 720 / GO 920 GO 530 / GO 730 / GO 930 GO 630 GO 740 (USA only) GO 540 / GO 740 (Europe only) GO 940 If you have further questions, please post a separate thread. I will update this thread as more information becomes available, or if Tomtom fixes the issue.