I'm having this problem with Lenny on multiple configurations of Dell Poweredge 1850 servers.
My configuration is LVM over RAID-1 (either software or hardware) with LILO. The ones without hardware raid controller will boot correctly after install. After several reboots it randomly generates the same error, and another reboot fixes the issue. The ones with hardware raid controller, however, won't boot after installation, I had to fix root parameter manually. In all of those cases "root" parameter was incorrect. While I'm not sure, I believe this is caused by "virtual media" drives of remote administration cards (In my case, VirtualFloppy and VirtualCD of "Dell Remote Access Controller 4").
