Suggest booting with a live linux cd and run #cfdisk /dev/sda on it to reveal the true partition structure, and which is the real boot partition -- it will be marked with an asterisk. Those hidden first parts are usually not very big, which makes for an easy and secure backup situation: just use dd to take a full image of that first part, and store it on some external media. Restoring that file [again with dd] will absolutely get you back the MBR and master partition table, along with the drivers that are usually stored in that first hidden part.
No I built it. But thanks anyway. /dev/sda is where it is located.