You rock !!!!!!!!!!
It works now !
I have applied the 2 tips above, and I got a message from Code::Blocks "OnDrawCanvasMouseLeave is not defined", or something like that.
I looked at the code, and I had a #if __WXMSW__ around this method.
Strangely, it was not compiled on Ubuntu.
Now everything is working. Just this simple thing !!
I will update the svn (using Windows, because I have added several files, and I do not want to forget them.
I have to reboot now.
Sebastien
PS : how do we do a screenshot in Ubuntu ?