Phantom Partition ... how do I correct this?

I've done a clean install twice since this appeared (not to fix this, as everything seems to be working). Gparted doesn't show any such partition. I'm about to do another clean install, so this is the time to get it right. Any advice on where to begin?

 marc@Thor:~$ blkid
 /dev/sda1: UUID="1bd1fc27-31da-4515-b1b1-2d4acea80abe" TYPE="ext4" 
 /dev/sda5: UUID="e54014fa-3d67-42c0-9532-b5b5efc35e5b" TYPE="swap" 
 marc@Thor:~$

 marc@Thor:~$ cat /proc/partitions
 major minor  #blocks  name

    8        0  312571224 sda
    8        1  308659200 sda1
    8        2          1 sda2
    8        5    3909632 sda5
   11        0    1048575 sr0
 marc@Thor:~$

 marc@Thor:~$ sudo blkid -p /dev/sda2
 [sudo] password for marc: 
 /dev/sda2: PTTYPE="dos" PART_ENTRY_SCHEME="dos" PART_ENTRY_TYPE="0x5" PART_ENTRY_NUMBER="2" PART_ENTRY_OFFSET="617322494" PART_ENTRY_SIZE="7819266" PART_ENTRY_DISK="8:0" 
 marc@Thor:~$`