Not actuallly sure what you mean but ...
i installed both of them but the same problem.
You could wait for the patch FO mentioned or follow what I posted. If you did so I'm 99.9% sure you'd have the 0.5 ffmpeg with vhook and x264 enabled.
You need to remove any prior x264 builds first and if you have any ppa that provides x264 then disable it.
You'd run this first, then install the karmic libx264-67 and karmic libx264-dev (1:0.svn20090621+git364d7d-0ubuntu2), then build the 0.5 ffmpeg source, ect.
sudo apt-get remove libx264-dev x264 ffmpeg
sudo apt-get install libx264-67 libx264-dev