I can't select H264 output because I have all red cross.
I have the latest version of Kdenlive 0.7.8 and MLT 0.5.10.
When I run the wizard configuration I got no problem, and all format seems correctly installed.
I can't choose also WebM option but this is not important for me.
I tried to install and re-install several times without result.
Can anyone help me ???

Bye

post what version of ffmpeg and which libraries you're using. What distro also.

another thing that's weird is that you're saying in the configure kdenlive part, it shows that H264 format is available?

Make sure kdenlive is NOT open, try locating and deleting the .kdenliverc file which stores that info. Its in your home folder somewhere. If you don't feel comfortable deleting it, then just move it to your desktop. After moving or deleting that .kdenliverc file, when you open kdenlive again it should walk you through the setup again. Good luck

I solved this problem, first uninstall all stuffs under ffmpeg in synaptic, then in terminal:
sudo apt-get install libavcodec-unstripped-52 libavdevice-unstripped-52 libavformat-unstripped-52 libpostproc-unstripped-51 libswscale-unstripped-0

then reinstal kdenlive and run wizard config under Settings ( http://img264.imageshack.us/img264/8305/dddddat.png ) and it should works! After this I needed install again SMPlayer and VLC and run config wizard in kdenlive again, and it's done ;) hope this help!