Bug#852653: additional info
I booted using the install disk and used the rescue option
Trying to install grub again from the mounted drive, it reported this
grub-install: warning: Attempting to install GRUB to a disk with
multiple partition labels. This is not supported yet..
grub-install: warning: Embedding is not possible. GRUB can only be
installed in this setup by using blocklists. However, blocklists are
UNRELIABLE and their use is discouraged..
grub-install: error: will not proceed with blocklists.
a quick search yielded this:
The first partition was indeed 2048 so I ran the command as suggested:
dd if=/dev/zero of=/dev/sdX seek=1 count=2047
and then grub successfully installed and it all boots correctly
Not sure if that helps...