I followed the Ubuntu instructions to install kdenlive 0.9:
sudo add-apt-repository ppa:sunab/kdenlive-release && sudo apt-get update && sudo apt-get install kdenlive
I then tried to run kdenlive and it complained about needing mlt 0.7.6, so I upgraded mlt and libmlt to 0.7.8. After that, kdenlive 0.9.0 starts up fine, but when I try to do anything, like add a clip or click the New... button, kdenlive hangs.
I found this thread http://kdenlive.org/forum/linuxmint-12-newbie-installation-mlt-errors and tried uninstalling kdenlive, mlt, and libmlt, followed by reinstalling everything from the svn repository: ppa:sunab/kdenlive-svn.
Again, the install completed with no errors, but when I run kdenlive, I get the same problem -- it hangs when I try to do anything with it.
Thanks in advance for any help. For now, I am unable to run kdenlive, and wouldn't you know it, I am in vital need of it at this particular moment.