rsiesta

I have seen several threads about inconsistent distance measurements when using gps on both runs and rides. I am using mapmyride and found an anomaly with a route
that has a turn around. I am curious of anyone that has distance errors are on a route that turns around and retraces steps and if anyone can suggest a way to fix this problem.
I did not understand what the problem was until one day I turned on realtime speed. I have a 1 mile route that has 3 culdesac so I ride around the circle and head back out
on the same road in the opposite direction. What I notice is the speed stays the same till almost the end of the circle, just as I am starting back out on the road part my speed dives
down to 1-2 mph and takes about a tenth of a mile to gradually climb back to the 10 MPH speed I have been going the whole trip around the circle and back out. The circle is
about 50' diameter so I am able to keep my pace the whole way around and back out. It appears the software is getting confused with its gps calculations and for a while thinks I am
going backwards so it slows my speed down. Since speed over time is what distance is I can see how this would make my route appear shorter then it really is, which is what I have
observed. Has anyone else experience this or have any suggestion on how to resolve it?

Ron