I installed Lenny in advanced mode and lived to tell.
I am proud!!! I am on top of the world.
When I was struggling so hard to install Debian GNU/Linux 3.0 "Woody" I was desperate to get a nice installation. After a thousand attempts I decided to try advanced mode. Back then I had no Debian experience whatsoever. I had no idea of how to answer to the prompts. I had to quit.
But after the years, I decided to install Lenny in VirtualBox with LXDE in expert mode. Now the installer has a menu to select the desktop environment. I chose LXDE and went on in expert mode and I got it!!!!!!!! It worked!!!