When you us the linkTrackVars make sure that when you provide multiple parameters they are only separated by a comma and that there is spaces between each of the elements.
BAD:
s.linkTrackVars=’prop1, prop2, events’;
GOOD:
s.linkTrackVars=’prop1,prop2,events’;
For some odd reason Adobe has made this implementation part of their best practices but they haven’t highlighted the importance of having it all without spaces between each element.