Comment 3 for bug 343640

it still happens as of today's jaunty (2009-03-29).

it's mentionned in kdenlive's forums:
http://www.kdenlive.org/forum/ubuntu-jaunty-jackalope-alpha-cannot-save-project

the answer from the developers on the forum about that issue is:

"There was a bug in Kdenlive that caused a crash with Qt 4.5 on document saving. It was fixed in svn, so you can either try to compile the latest svn or wait for Kdenlive 0.7.3 which I hope to release somtimes in april."

I hope ubuntu upgrades the package before release or it won't be very useful if it crashes when saving the project :-(