I also just looked at "Observation Post" (the one you looked at). I get 50 degrees 55.916 minute, and 01 degrees 45.435 minutes in all 4 cases. Again, a prefect match. And it's not a format conversion problem. In degrees, minutes, seconds I get I get N 50 55'54.950'' E 01 45'26.091' in Locus and in GE.
When you say "When I put the crosshairs on the actual location it should be at", what do you mean? If you look at the information for the POI what does it say? If this doesn't appear to match the map, which map are you using?