Garmin 110 Sync UGH!

This is a common problem- often happens to those clip-connectors. Two of the four contacts are for charging and the other two are for data transfer. So you can have charging with or without data transfer, and vice versa.

One thing that often works is cleaning the contacts (on the watch and on the charger clip). Try rubbing them with a rubber eraser-- that often works. Also make sure they are clean and dry after you take off the watch if you are sweating, etc.

Good luck.