Video files on my K7 have always broken index
I frequently have this problem as well. My camera is the K-x. I have learned to ignore the warning. On Windows7 x64 professional the same video files play just fine with Windows Media Player. Sony Vegas Movie Studio 9 & 10 haven't complained about the video files either, so I've been assuming it is an issue with VLC.
|_MG_5100 by tim and jan|
from Welcome to the Saloon!
|The Grimm 11 year old by Ryan Gardner|
from Trick or Treat
|Heron with fish by APenza|
from A Big Year - birds