I'm having an odd problem with my Sigma cyclocomputer. The computer was not synching with the transmitter, so I thought I needed to replace the transmitter battery. Put in a new battery, still couldn't get it to register. Then I discovered the magnet had gotten shifted, which I fixed. Spun the wheel by hand and got a reading; great! My next ride to work, I can't get it to synch. Before riding home, I spun the wheel again and it read. Disconnected after about 2 miles, couldn't get it back. Let the bike sit at home for a couple of hours, again spun the wheel with success. Nothing has changed in the setup other than the magnet problem which has been fixed. Can't figure out why it will receive a signal when I spin the wheel by hand, but lose it when I'm riding.