Dark screen when booting debian-kernel 2.6.11

[Hubert <hmauchle@magnet.ch>]

I'm currently running a Debian Kernel 2.6.10 and I
recently downloaded the kernel-source-2.6.11-1 package.
My installation is basically a Knoppix 3.7 that was transferred to hard disk.
I shortly did apt-get dist-upgrade with my config-files pointing to Sarge.

I called make oldconfig with my current .config-File.

After getting over the problem with qal2xxx, I got my
new kernel-image compiled and installed, but if I boot,
the screen blacks out.

I tried "make oldconfig" several times, and at the end I didn't accept any of
the new configuration items, but all I see after I choose
the new kernel at bootup are the three lines of lilo output and then
my screen gets dark. And stays dark.

Which additional information should I provide?

Thank you and Regards
Hubert