how can i know which of the preference settings are important? there are just some files i don't know which kind of. so what kinds of files do i have to save or make a note of?

i just tried to drag the incomplete file into the vlc-player: there is just a black screen and in the timetable the file is playing much faster than it should do... yes, the file is just as big as the correct file should be. thats why i'm wondering about.

i had this problem about three loaded files.. i don't think that they are all the three corrupt. this would be a great hazard, wouldn't it?