Today we ran a pocket query of Apache Junction caches and downloaded the info into our Garmin 60 CS.  We also downloaded the same file into a pda.  However, the coordinates in the Garmin did not match the coordinates on the PDA for one particular cache.   I checked the cache description on line and the PDA matches what is on line. The Garmin is wrong. This has actually happened more than once.  Usually it is just an inconvenience and we catch it right away. Today it cost us an hour of searching in rough terrain at the end of a hike and we did not find the cache.  Can any one explain what is happening?