Map location ?

Hi folks, not sure but I believe at one time my spot on the USA map was pretty close to my location but happen to check out the live map and noticed I was up in New Hampshire. I never did set the lat/long numbers, either on the site or within Radmon itself so I tried to do that and did manage to get it somewhat closer but not really close enough. I only put in the one set of numbers to the right of the decimal point and was off so I tried the second set of numbers and it won't move. I suppose its close enough but would like to get it closer to were I really am. Are the settings we put in really only crude ones and it just gets us in the ball park? Or is there something I am missing. Ex: If I put in say 42.25N it puts me about 1/2 mile from where I am, if I put in 42.24.25, it doesn't budge. Only reason I like it close to where I am is I have an active railroad track about a 100 yards away from my house and at the current location on the map, it has me about a 1/4 mile from the track.I monitor this area for just this reason, never know whatss being hauled around.   Thoughts?  thank you    Frank   

The lat/long must be in decimal degrees, not deg.min.sec format.  And + or -, not N or S.  For example, try 42.244.