Distance wrong again

Have a route on basecamp and on my eTrex30 on the same topo 24k map with the same routing options and the distance is wrong on the device. The distance was longer but as I removed way points, it became shorter. The route is now only 9 points for a 10 mile loop, so it shouldn't be an issue. Anyone experience anything similar? The route started 3 miles longer and is down to only .4 miles longer but obviously something is going on here.