I have noticed that sometimes my 245, maybe 1 in every 20 runs the GPS goes a little odd. For example tonight it was fine for the first mile then all of a sudden it shot me about 15 metres on the other side of the road. Then for the next 5 miles it tracked my movements but always that 15 metres out.
As a result of this the distacne was correct tut the map looked off as i was paralell 15 metres out.
Anyone else noticed this?