Cant see sequence content in CS6 Premiere

I have a multi sequence (25 sequences or so) in a action sport multicam project. After some day’s of editing some of the sequenses stop showing contents in timeline. Some show other sequence contents and some show nothing. When I play I hear sounds in the sequence but no contents shown in timeline. It’s kind of hard to edit when you dont see anything…  🙂 I tried to save to a new name but no difference. I try to make files offline and relink them but nothing. Is it a bug or have I missed something so I should be ashame?

via Adobe Community : Popular Discussions – Adobe Premiere Forums http://forums.adobe.com/thread/1115612