I upgraded to precise recently and had so many issues that I would like to share with you my headaches.
My computer is an Acer Aspire 5560 laptop with an amd A4-3300M processor and a built in radeon 6480 graphic card.
Before the upgrade I had Mint 12 installed in dual boot with windows 7.
The First time I installed Precise I went into custom partition mode, formatted the existing linux partition and simply installed Precise there. After reboot I get a black screen that says something like ELF magic error, grub rescue mode. I didn't panic, and I used the live cd to install grub through the command line. The terminal confirmed that grub was successfully installed. I rebooted and got again the ELF error and grub rescue.
The Second time I thought that maybe I had done something wrong, and reinstalled all over again from a different ubuntu spin. Same grub rescue error.
The Third time I tried with another distro. Debian testing installed fine with netinstall. And after installation I even got the grub menu, But the distribution actually couldn't load because of an issue with my GPU (LOL), giving me just a black unusable screen.
The Fourth time I decided that to better understand what was the matter I had to completely clean up my HDD. So, from the ubuntu live cd I destroyed the 3 partitions I had on my HDD: the linux partition, the windows partition, and the windows boot partition. I made just one big partition for ubuntu and I installed it.
This time I got this message that was saying "No Operating System Found".
The Fifth time I reinstalled ubuntu with the option "Install Ubuntu using the whole HDD". Installation went fine and now i even get grub sometimes (this is actually very puzzling, as I get it only every now and then).
What Ubuntu did that I did not is that it created an EFI partition. So, I'm asking, what do I need an EFI partition for? I have been using linux for years and I never had the need for an EFI partition.
I hope someone will have some explanation for me, or at least some theory XD.