I think that the vast majority of patterns have a mistake in them, somewhere.
It's like the software companies now - they want to get a "new" product out the door so fast, they don't do sufficient testing.
Sometimes it's the designer's fault, sometimes it's the publisher's fault.
I can't decide if it's laziness or impatience... perhaps it's both.
But that's GREAT that MSQC has that kind of customer service mindset!! I love Jenny Doan's tutorials - she's such a hoot to watch!! I think my favorite so far is her tute for the Creative Grids Pineapple ruler - she's just so obviously tickled at how accurate her blocks turn out with that ruler!! Her enthusiasm is so darn cute!!