Same issue here upgrading from Dapper to Edgy. I also have beryl and nvidia-glx-dev installed. Here is the relevant part of the main.log
2006-11-23 11:18:52,002 DEBUG The package 'nvidia-glx-dev' is marked for removal but it's in the removal blacklist 2006-11-23 11:19:14,603 ERROR Dist-upgrade failed: 'A essential package would have to be removed' attached is apt.log ** Attachment added: "atp.log" http://librarian.launchpad.net/5150705/apt.log -- Package nvidia-glx has broken dep on nvidia-kernel-1.0.9625 https://launchpad.net/bugs/70195 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs