X crash when I try to edit some titles...

Hello everyone,
I'm pretty new to kdenlive and I don't know if it's a bug or just something wrong with my machine but I noticed that kdenlive crashes the X server when I try to edit some titles... Or when I enlarge the preview window... And now I realize that happens when my title is actually bigger than the frame size... I made a quick video with my phone for you to understand better :


So is it a bug ? I'm using ubuntu 10.10 64bits and kdenlive 0.7.8 from the sunab ppa. Oh yes and I found that the installed version of mlt is 0.7 and the recommended version is something like 0.5 , so I wonder if this might cause a problem ?? (I don't think considered that the 0.7 package is provided to me via the sunab ppa...)
And I'm working with a PAL project. And sorry for my clumsy english, I'm tired, and french hahaha...


Yes, mlt 0.7.x is too new for the release version of Kdenlive 0.7.8. It should be mlt v0.5.10.