sony vegas 8 rendering problem

ok there is a problem:

i am using sony vegas 8, after rendering there is not even one effect which i added to a movie, i tried to do it by Video Event FX, Video Outpot FX, Media FX and nothing works; it works only with uncompressed settings taken from my project; but this file is too big for me, i wanted to use huffyuv v.2.1.1., but it doesnt work - there are no effects :x i tried other codecs and it was same situation, it seems that it works only with uncompressed settings

any help/suggestions?