It's really not a Norco thing. Just within my riding group we've had North Shore racks play badly with YT's and some Rocky Mountains as well as my Aurum HSP. Add this to Evils the other commenter mentioned and we're starting to compile quite a list!
It was one of the main reasons I swapped my NSR out for a Hangover this past spring. NSR's been behind the times for years at this point.