Is anyone shocked that a GPS based speed/distance sensing element will lose lock with the Sattelites occasionally? Top of the line Garmin GPS (automotive) lose connections during severe weather and in when certain kinds of infrastructure are around. I've had any number of Sigma and Cateye 'computers' and they really don't warrant much discussion. No point getting too specific because what I tell you to get may not even exist. Just look for 'wired/wireless bicycle speedometer/odometer' at your favorite LBS (or on Universal Cycles online) and make a selection from the small amount of units on offer.