Was working perfectly a week ago.
Ubuntu Precise and Kdenlive 0.8.2.1 (melt 0.7.6).
Tried to render a new project today and only audio is rendering. Loaded an older project that rendered fine previously and the same thing is now happening.
My usual rendering format is h.264, but the same thing is happening to all other formats (.avi formats won't render at all and just crash).
Have done nothing out of the ordinary other than install xcfe desktop - would this break rendering? (same issues occurring if I switch back to Unity).

Not sure what was wrong, but the advice from this newer thread - http://www.kdenlive.org/forum/unable-render-produces-almost-empty-file - seems to have fixed the audio only issue I was having.