VideoCapture & Python returns False trying to read a video file

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When i try to read some video files using VideoCapture, i only get False in return. I did try it on my Pi and Windows 8.1, using OpenCV 2.4.10 on both systems. Python 2.7.3 (Raspberry PI) and 2.7.5 on Windows. So far all needed codecs are installed, on the Pi ffmpeg. ffmpeg Works on the Pi. Did also try to read a mpg video using pygame and it works. I can successfully read images or directly from webcams but so far no videos from a file and i did try a lot of codecs so far.

Did try to run Python in verbose and also did try to find some logs who may help me find my mistake. So far without any luck.