Fade in colors are not smooth!

How to fix this color bug in fade in effect?

http://s2.postimage.org/oplsvqjpj/223434444.png

And why I can't get libx264 in kdenlive? I have instaled x624, libx and dev fildes, and reinstalled kdenlife, run configure wizard but can't get h264 working!
What's wrong? :(

hope to fix this!

Regarding x264, What distro? What version of kdenlive?. Try installing libavcodec-extra-53, then delete kdenliverc in /home/.../.kde/share/config, rerun the kdenlive config and test.

Oh Oh Oh :D Thx, that help, now x264 is working :)

By the way, Ubuntu 12.04, Kdenlive 0.9.2, MLT 0.8.2.