One ski has rockered?

it depends on what the rockered ski flexes like, if it flexes significantly softer than the other ski, or there is one point where it flexes a lot but the rest is, it means you most likely cracked the core and i wouldn't continue to ski on them. if the flex is pretty normal then you could have just bent the core by stressing it doing something like nose-presses or butters, you could still ski them if its like this however it might be more likely to break at that point.

How long have you had them? Skis wear out and lose shape and flex. This is what we call dead skis. I've had this happen plenty times before, theyre just worn out from skiing. You need new skis there bud. Also, I've never had any problems with the durability of the skis, never had them break.