audio keyframing question

running on Ubuntu lucid, not sure which version of kdenlive (don't have computer with me to check it) but it was recently installed so its probably 0.7.6 or 0.7.7.

I set keyframes into the audio track to attempt to mute a particular section, keyframe controls show up and work as expected, but when I play the video in the project monitor there is no change to the audio levels. Tried it with combined video/audio track and with separate tracks, same result. Do I need to render or something to enable the keyframe effects, or is this a bug that I should report?

Please report your kdenlive and mlt versions.

When it wasn't working I was using kdenlive 0.7.7, but didn't check the version of mlt. The kdenlive configuration command didn't complain about anything so I assume I had the latest version of mlt as well, but I didn't check the version number for sure.

I reinstalled everything from scratch and now it works OK.

In my previous attempt I originally had an earlier version of kdenlive installed which eventually got updated to 0.7.7. I removed everything and reinstalled Ubuntu Lucid without any previous version of kdenlive on the system, then installed kdenlive for the first time directly to 0.7.7 after reinstalling Lucid.