There is NO problem at all in taking it again. In fact to hunt in some states,
your "old" hunter ed card will not be accepted... you need a new one. The
course has changed dramatically since the '70's. Still pretty basic, but covers
a lot more areas.

Often times parents will show up & stay with their kids, and ask since they will
be there anyway, can they take the class as well. It's usually not a problem...
(I can't ever remember saying no).