On a funny note; i read today that fdisk also has an option to "fix" an existing partition table (under expert options)...
I did try that once and I won a free system reinstall, maybe I was just unlucky or the partition table was too messed up.
Looks like the partition table is stored on the first sector of the disk, so restoring a copy of that sector also restores the table. But yes; storing a copy of the MBR on an external disk is what i meant.
That will only restore the primary partitions (the extended partition itself is a primary partition), the location of the logical partitions inside an extended partition are saved in a different way, check [1] for a description. With luck, by restoring the extended partition one can also restore all the logical partitions inside.
You're right, it wasn't neccesary in this case, but it sometimes happens that the order of partitions get messed up. On such occasion it might be worthwhile to just recreate the whole table.
As far as I know linux doesn't care if the partition order in the table is the same as the order on disk but lots of partition managers complain (and I like it to be nice and ordered). fdisk can create an out of order layout (at least it did for me once), cfdisk can do that too I think and gparted is a master at messing with that when doing any operation with partitions (and thats why, among other reasons, I try to touch gparted only with a long stick). Now that we are talking about this I guess it is a good time to share thoughts/experiences about this, you never know when knowing this things will prove to be life savers or avoid you from making big mistakes. [1] http://en.wikipedia.org/wiki/Extended_boot_record