[dennisw]

I have to twist the cord right where it meets the jack. Do the cords get crimped inside and cause these problems?

No crimp inside
Most likely point of power cord failure is where the cord connects into the plug  (jack)  that you insert into the laptop.  Through lots of bending and manipulation (I kind of doubt you are doing this) it becomes frayed at that point. Gets frayed within where you cannot see it

 

[mom4kittys]

I wisk it was easy to tell. I'm pretty sure it is the jack now. The computer is only about a year old and I've already been through a couple of cords. (One time thanks to my kitten though, so that doesn't count lol!)