I am rendering (h264) without problems but when I add a Title Clip and composite transition, rendering results empty file without any errors. The same result is given changing the Transition to any other type I tried.
Also generated a script and executed from shell but the result was the same. No error mentioned, empty file created.
Any help would be appreciated..
KdenLive Version 0.8.2.1
KDE -Platform Version 4.8.2 (4.8.2)
Ubuntu 12.04LTS

Didn't see your post... even if I searched a lot about this issue...
I thought the problem was the Transition, but you are correct. Transition seems to works until a Title Clip is inserted... :(