Hi!
I just ran into some trouble with Kdelive when using the same video clip multiple times in a project. At some positions I want to fade/blend from one part of it to another (simply by using two video tracks and a fade). All works fine in the preview window. But when I render the video, there is immediately the target clip visible without any alpha translucency during fading. I tried out many things (different video types, other video input, etc.), but I couldn't get it work. Finally, I tried fading between different video files - and all was fine.
So it seems that it is not possible to fade from a video file to another position inside the same video file? Can anybody confirm this? I tried Kdenlive under Ubuntu 10.04 and Ubuntu 10.10 with an error-free installation of Kdenlive.

I just successfully accomplished this when I was removing dead spots from an interview by making short dissolves between the shots all taken from a single file.

I do remember this being a problem in a recent version that was fixed in v0.7.8. What version are you using?

The repositories for Ubuntu 10.04 deliver Kdenlive 0.7.7.1 under KDE 4.4.2 with MLT 0.5.4.1, and the repositories for Ubuntu 10.10 deliver Kdenlive 0.7.8 under KDE 4.5.1 with MLT 0.5.6.

Unfortunately, the problem occurs in both systems, so also in 0.7.8, at least when editing an MPEG-4 or an MPEG-2 video. With the MPEG-2 video I even got some frames lost and interrupted audio during the time of the non-visible fade in the rendered video output. The preview works and shows the fade, but it is much slower than fading between two different video files.

Anyway, I just found this page: http://www.kdenlive.org/user-manual/downloading-and-installing-kdenlive/pre-compiled-packages/ubuntu-packages where they advise not to use Kdenlive from the official repositories, but to install Kdenlive 0.7.8 with MLT 0.5.10 from some ppa. Well, I just did this and now all works like a charme! So, perhaps the problem was more or less caused by some too old MLT version. However, problem solved! Solution: update to the most recent Kdenlive/MLT versions from the ppa mentioned at the above link.

Thank you for your hint!

Not sure how you got the combination kdenlive 0.7.8 with mlt 0.5.6 because the kdenlive 0.7.8 build requires mlt 0.5.10, and Maverick still only has kdenlive 0.7.7.1:
http://packages.ubuntu.com/maverick/kdenlive
Anyways, I am glad you resolved it.