Comment 4 for bug 727842

OK, reproducing this was fairly easy. I started with this arrangement on sdb (my testing drive):

Model: ATA WDC WD800JB-00JJ (scsi)
Disk /dev/sdb: 80.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
 1 32.3kB 38.4GB 38.4GB primary ext3 boot
 2 38.4GB 80.0GB 41.7GB extended
 5 38.4GB 77.4GB 39.0GB logical ext4
 6 77.4GB 80.0GB 2665MB logical linux-swap(v1)

So once again the whole disc was occupied. I booted choosing "Try Ubuntu" to get to the live desktop, then chose to install. I then ran through the "alongside" install process without error and then hit "Back" before the process completed just to expedite testing. After quitting the process I used Gparted to delete sdb5 and tried to use the "alongside" option again. At that point I got the same error that resulted in this bug report.

Next I wanted to see what happened if I chose "Install Ubuntu" rather than "Try Ubuntu" so I rebooted and upon trying "install alongside" the "spinning wheel" would just spin forever instead of progressing. After several minutes I just pressed alt>sysreq>k, then chose to boot classic w/o effects and used Gparted to create a blank ext2 partition where the unallocated space had been. Then upon restarting and choosing "Install Ubuntu" the "alongside" option proceeded as it should. But once again I quit the install before it completed just to expedite reporting on this bug.

I wonder if I should try this with sda disconnected but that seems rather pointless. I'll wait for Evan Dandrea or someone that really knows ubiquity to request more info ;^)