HELIX 5 SONAR GPS - Software version 7.730
Unit works great when converting .kml > .gpx > MyhumminbirdPC for uploading waypoints.
However, when trying this for Tracks, the unit freezes up every time.   
I have tried:
Restoring factory defaults, clearing all waypoint and track data, uploading only 1 single (5 point) track.  Unit Freezes
Saving track as a .kml then converting to .ht via gpsbabel, then uploading through MyhumminbirdPC.  MyhumminbirdPC forces the .ht file to be converted to .gpx then put it on my card.  Unit Freezes
I have worked with Humminbird technical support for days, and we cannot solve the issue.