A lot of it is the shops' fault, there have been a lot of skis that shouldn't have been put on the wall for sale to begin with. The simple fact is, some pairs will have no problems and hold up great, others have been shown to have defects. New manufacturing process is bound to have a few bumps along the way... in this case, it's a consistency issue. By no means are the invaders bad skis. They're good for the price. SOME invaders have durability issues.
That's been my impression, and I don't know why this discussion is even still going on now that everyone's aware of how things are. The most promising thing is that even people who HAVE had durability trouble have been saying "It's a shame, too, because the skis are amazing/sick/really fun". So, you can buy them now, and probably won't have problems (the minority is louder in this case, make no mistake about that), or wait until next year.