Add avi file to Sony Vegas -> only audio line, media offl

Hey if i add a simple avi file to Sony Vegas 8.0 (ofc registered) i just see the audio file, i cant add it to Video Track. Whats the problem?
And if i add HD .mp4 file, i just see a big black lane at the video track, and only audio running. I have quicktime.
Help me please
Answer #1
I suppose it’s codec issue..
Download latest k-lite codec pack and/or FFDSHOW.
Answer #2
Solved! Thanks .
Answer #3
No problem, happy to help
Answer #4
it oesent work for me using win7 64bit on vegas pro 9, tried so DAMN many codec packs …