Comment 1 for bug 537849

I have the same problem described above. I installed 10.04 from optical media, later i added serial console support for kernels and GRUB2. Kernel support works fine, but GRUB2 menu cannot be seen on serial console, just the error messages described above. I ran aptitude update & upgrade, but no changes. I have the deafult package repositories. Only "grub-common" and "grub-pc" is installed from the many grub packages.

Conclusion: in 10.04 LTS the bootloader's serial console is broken and not possible to use it, eg. to boot into safe mode.