[Nikos Qwer]

weak computer performance is kinda impossible. i have an i7 950 quad-core cpu with 8GB ram and an Asus HD5870 gpu.windows 7 ultimate 64-bit
well im not very familiar with videos formats etc, but the video is
taken from mobile camera in .mp4 format.
as i told you many of my videos(from cameras or not) appear black in the vegas. so did this one
i tried converting this one into .avi using free 3gp converter and again tried from avi to mp4. none of the 2 worked(same problem ,they appeared black)
after installing k-lite mega codec,only the one converted into .avi worked, but showed the problem i described previously, with the multiple tracks playback.
reducing the quality i think is not related. the black playback appears with many other videos (good quality or not) and the multiple tracks problem appears in all the videos i have tried.