Codec missing for .MOV file

[impro1]

Hello,

I've got a macbook pro with mac osx 10.5.8.
I dont seem to be able to play .mov files on the mac, because i can hear sound but dont see visuals.

Even in adobe premier i can import .mov files but the same thing happens (sound but no visuals).

Right now i have installed quicktime player 7.7 but what is wrong. Please help me because i cant finish editing a movie in premier..

Thanks in advance!
peace