Blueprint editor does not open (linux)

I can’t open the blue print editor.
Double clicking in content browser or clicking edit in worl outliner as no effect.
Perhaps one effect : it seems frame rate of the editor lowers, and cpu usage increase.

Actually, after resetting the layout (which I had not really changed because it was a fresh build), it’s appearing.
I’m on kubuntu 6.10 with kde.
Perhaps default layout is buggy?