All render formats I have tried give me empty files. And, if it helps, many of the formats are unavailable in the menu. I am a COMPLETE newbie in kdenlive and ubuntu 11.04, so I'll need like STEP BY STEP instructions. Thanks!

Step 1: Search the forum
Step 2: Follow the instructions given in the threads

There are a number of threads dealing with ubuntu related stuff and empty output files.

the only two plausible solutions i could find were

installing sudo apt-get install libavcodec-unstripped-52 libavdevice-unstripped-52 libavformat-unstripped-52 libavutil-unstripped-49 libpostproc-unstripped-51 libswscale-unstripped-0 , which returns:

Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package libavcodec-unstripped-52
E: Unable to locate package libavdevice-unstripped-52
E: Unable to locate package libavformat-unstripped-52
E: Unable to locate package libavutil-unstripped-49
E: Unable to locate package libpostproc-unstripped-51
E: Unable to locate package libswscale-unstripped-0


and checking if the drive is full, which for me, it is not.

OK. Seems as if you are missing a repository containing the "restricted" ubuntu stuff. I am on Arch linux and therefore I can only hope, that this link helps you to get access to the restricted stuff: http://www.dagorret.net/2011/05/26/install-ubuntu-11-04/ (There is a section about unstripped stuff)

Or some nice ubuntu user here helps out with help "how to get access to restricted stuff". ;-)

Open Ubuntu software center and type ¨multimedia¨ this will bring an item non free mm extra´s forward.

If that was the problem, it should be fixed after this install.
Rinus

It worked! I didn't get a chance to try the software center method, cause the link to the text to put in the terminal worked immediately. Why aren't these things pre-installed in ubuntu?

copyright issue, I guess