Hi I can confirm this bug too. I definitely agree with the change of severity to grave.
In my case, I tried to install a large number of packages on a fresh Lenny system, in which a dependency of one required udev to be upgraded to the latest version. I received the same error as Pierre-Alexandre and my system was basically deadlocked. It would not let me upgrade the kernel first as it wouldn't properly process the installation without first solving udev, which itself of course could not be resolved without installing the new kernel. There are probably various ways around it, but all of them require manually working around the issue. I frankly decided it would probably be less problematic to just reinstall Lenny completely and upgrade the kernel first. I found version 2.6.30-8squeeze1 works fine. This avoided any potential issues I may cause by fiddling around. From the point of view of any inexperienced Linux user, this issue will be somewhat daunting. Orion -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org