Merging GIS Tracks - Harbor Springs Chapter

For the last 3 days, I've been merging tracks for the Harbor Spring Chapter of the North Country Trail Association in Lower Peninsula Michigan with GPS Visualizer.  For North Country, it's about 63 miles, so it not a large span.  It's definitely shouldn't be that challenging for GPSVisualizer.  I've seen it twice that distance in to one track and get the elevation profile right.

This picture is a screen shot displaying the merged path/ track with some of it's original data and an elevation profile.  In that profile, the outline of the chart should be in solid red.  And look at those straight drops between Miles 40 and 50.  I've never been on this section before.  But that also looks like an error.  The original track elevation profiles work.  It's just that merged all 63 miles together three separate times and can't get the elevation profile working.  I'm going to move on to a different chapter.  If the errors show up there too, then I can probably say that GPSVisualizer is having a bad day.